Information transmission method, user equipment, and base station

ABSTRACT

Embodiments of the present application provide a method for acquiring information of access resources, a terminal device, and a base station. A terminal device detects a synchronization signal of a cell to be accessed by the terminal device. The terminal device further receives a broadcast channel of the cell on a broadcast channel resource. The terminal device then determines a resource on which the cell is located according to resource indication information carried in the broadcast channel. The broadcast channel resource corresponds to an actual access resource, and the synchronization signal is detected on the actual access resource. The actual access resource is one of a plurality of candidate access resources of the cell. The resource indication information indicates a location relationship between the actual access resource and the resource on which the cell is located.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/947,876, filed on Apr. 9, 2018, now U.S. Pat. No. 10,687,332. whichis a continuation of U.S. patent application Ser. No. 15/217,542, filedon Jul. 22, 2016, now U.S. Pat. No. 9,961,681. U.S. patent applicationSer. No. 15/217,542 is a continuation of International PatentApplication No. PCT/CN2014/087549, filed on Sep. 26, 2014. TheInternational Patent Application No. PCT/CN2014/087549 claims priorityto International Patent Application No. PCT/CN2014/071323, filed on Jan.24, 2014. All of the aforementioned patent applications are herebyincorporated by reference in their entireties.

TECHNICAL FIELD

The present application relates to the communications field, and inparticular, to an information transmission method, user equipment, and abase station.

BACKGROUND

In a Long Term Evolution (LTE) system release 10 and earlier releases, aprocess of accessing an LTE system by user equipment (UE) includes thefollowing:

The UE detects a primary synchronization signal (PSS), and then asecondary synchronization signal (SSS) by using a time domain locationrelationship between the two, so as to achieve an initialsynchronization of time and frequency. The initial synchronizationincludes symbol, subframe, and frame synchronization. The UE furtheracquires a physical cell identifier by using a combination of sequencesof the detected PSS and SSS. A length of a cyclic prefix is determinedaccording to a time interval between the PSS and the SSS. Then, the UEdetermines a cell-specific reference signal (CRS) to measure a cell. Ifa measurement result is relatively good, the UE reads system informationA physical broadcast channel (PBCH) is first read to obtain informationsuch as downlink system bandwidth, CRS antenna port, system framenumber, physical HARQ indicator channel (PHICH) configurationinformation. Then, a first system information block (SIB) SIB1 is read,and other SIBs are read according to configuration information of theSIB 1. For example, a second SIB 2 is read to acquire random accessconfiguration information. On the foregoing premise, if a servicerequires transmission, random access request may be sent to a basestation to establish a radio link connection to the base station, andthen normal data transmissions can be performed.

However, when base stations, especially micro base stations, are denselypopulated, in a synchronization system, interference between cellsmanaged by the micro base stations is quite serious, making it moredifficult or even impossible for the UE to read a common control channelof a cell.

SUMMARY

Embodiments of the present application provide an informationtransmission method, user equipment, and a base station, which cancoordinate inter-cell interference of a common control channel, andimprove performance of detection on the common control channel.

According to a first aspect, a method for acquiring a cell accessresource is provided. A user equipment device (UE) determines at leastone candidate sequence of a synchronization signal of an access cell ofthe UE, and multiple candidate access resources of the access cell. Acorresponding location relationship exists between each candidate accessresource in the multiple candidate access resources and a resource onwhich the access cell is located. Any candidate sequence in the at leastone candidate sequence corresponds to one of the multiple candidateaccess resources. The UE detects the synchronization signal according tothe at least one candidate sequence. The UE determines a resourcelocation of an actual access resource corresponding to a detected actualsequence in the access cell. The determination is according to thelocation relationship between each candidate access resource in themultiple candidate access resources and the resource on which the accesscell is located, and a correspondence between the any candidate sequencein the at least one candidate sequence and the multiple candidate accessresources. The actual sequence is one of the at least one candidatesequence, and the actual access resource is one of the multiplecandidate access resources.

With reference to the first aspect, a first possible implementationmanner is provided. The UE determining resource location of an actualaccess resource corresponding to a detected actual sequence in theaccess cell includes that the UE determines the actual access resourcecorresponding to the actual sequence from the multiple candidate accessresources. The UE then determines the resource location of the actualaccess resource in the access cell according to the locationrelationship between the multiple candidate access resources and theresource on which the access cell is located.

With reference to the first aspect or the first possible implementationmanner of the first aspect, in a second possible implementation manner,the candidate sequence is a complete sequence; or the candidate sequenceis a segment in a complete sequence.

With reference to the first aspect or the first possible implementationmanner of the first aspect or the second possible implementation mannerof the first aspect, in a third possible implementation manner, besidesa first candidate access resource, at least one candidate accessresource exists in the multiple candidate access resources. The firstcandidate access resource is a resource having a frequency domain widthof N resource blocks in a center of the access cell, and N is apreconfigured natural number.

With reference to the first aspect or any of the first to third possibleimplementation manners of the first aspect, a fourth possibleimplementation manner is provided. After the UE determines a resourcelocation of an actual access resource corresponding to a detected actualsequence in the access cell the UE determines a location of a centerfrequency point of the access cell according to the resource location ofthe actual access resource in the access cell.

With reference to the first aspect or any of the first to fourthpossible implementation manners of the first aspect, a fifth possibleimplementation manner is provided. After the UE determines a resourcelocation of an actual access resource corresponding to a detected actualsequence in the access cell, the UE receives a broadcast channel of theaccess cell. The broadcast channel carries bandwidth indicationinformation of the access cell. The UE determines a bandwidth of theaccess cell according to the bandwidth indication information.

With reference to the first aspect or any of the first to fifth possibleimplementation manners of the first aspect, in a sixth possibleimplementation manner, after the determining, by the UE, a resourcelocation of an actual access resource corresponding to a detected actualsequence in the access cell according to the location relationshipbetween each candidate access resource in the multiple candidate accessresources and the resource on which the access cell is located and acorrespondence between the any candidate sequence in the at least onecandidate sequence and the multiple candidate access resources, themethod further includes: if the actual access resource includes a firstactual access resource and a second actual access resource, acquiring,by the UE, a first random access configuration and a second randomaccess configuration on the first actual access resource and the secondactual access resource, respectively, where the first random accessconfiguration corresponds to the first actual access resource, and thesecond random access configuration corresponds to the second actualaccess resource.

With reference to the first aspect or any of the first to sixth possibleimplementation manners of the first aspect, in a seventh possibleimplementation manner, after the determining, by the UE, a resourcelocation of an actual access resource corresponding to a detected actualsequence in the access cell according to the location relationshipbetween each candidate access resource in the multiple candidate accessresources and the resource on which the access cell is located and acorrespondence between the any candidate sequence in the at least onecandidate sequence and the multiple candidate access resources, themethod further includes: determining, by the UE, a second referencesignal that is at the resource location of the actual access resource,where the second reference signal is a reference signal segment clippedfrom a first reference signal and corresponding to the resourcelocation, and the first reference signal is a reference signal generatedby using the center frequency point of the access cell as a center andusing a quantity of resource blocks included in the bandwidth of theaccess cell as a frequency domain width; or determining, by the UE, asecond reference signal that is at the resource location of the actualaccess resource, where the second reference signal is a reference signalsegment clipped from a frequency domain center of a first referencesignal and corresponding to a first frequency domain width, the firstfrequency domain width is a frequency domain width occupied by theactual access resource, a reference signal in the bandwidth of theaccess cell is a cyclic shift of the first reference signal, and thefirst reference signal is a reference signal generated by using thecenter frequency point of the access cell as a center and using aquantity of resource blocks included in the bandwidth of the access cellas a frequency domain width.

With reference to the first aspect or any of the first to seventhpossible implementation manners of the first aspect, in an eighthpossible implementation manner, after the determining, by the UE, aresource location of an actual access resource corresponding to adetected actual sequence in the access cell according to the locationrelationship between each candidate access resource in the multiplecandidate access resources and the resource on which the access cell islocated and a correspondence between the any candidate sequence in theat least one candidate sequence and the multiple candidate accessresources, the method further includes: if the resource location of theactual access resource is not a frequency domain center location of theaccess cell, processing, by the UE, a subcarrier in a center of theactual access resource as a virtual direct current subcarrier whendetermining division of resource blocks in the actual access resource.

According to a second aspect, a cell access resource indication methodis provided. The method includes: determining an actual access resourceof a current cell and an actual sequence of a synchronization signal ofthe current cell, where the actual access resource is at least onecandidate access resource in multiple candidate access resources used bythe current cell to send the synchronization signal, the actual sequenceis one of at least one candidate sequence of the synchronization signal,and any candidate sequence in the at least one candidate sequencecorresponds to one of the multiple candidate access resources; andsending the synchronization signal on the actual access resource byusing the actual sequence.

With reference to the second aspect, in a first possible implementationmanner of the second aspect, the one of the at least one candidatesequence is a complete sequence; or the one of the at least onecandidate sequence is a segmental sequence in a complete sequence.

With reference to the second aspect or the first possible implementationmanner of the second aspect, in a second possible implementation manner,besides a first candidate access resource, at least one candidate accessresource exists in the multiple candidate access resources, the firstcandidate access resource is a resource having a frequency domain widthof N resource blocks in a center of the current cell, and N is apreconfigured natural number.

With reference to the second aspect or any of the first and secondpossible implementation manners of the second aspect, in a thirdpossible implementation manner, the method further includes: sending abroadcast channel in the current cell, where the broadcast channelcarries bandwidth indication information of the current cell, and thebandwidth indication information of the current cell is used forindicating a bandwidth of the current cell.

With reference to the second aspect or any of the first to thirdpossible implementation manners of the second aspect, in a fourthpossible implementation manner, after the sending the synchronizationsignal on the actual access resource by using the actual sequence, themethod further includes: if the actual access resource includes a firstactual access resource and a second actual access resource, sending afirst random access configuration of the current cell on a broadcastchannel resource or common channel resource corresponding to the firstactual access resource, and sending a second random access configurationof the current cell on a broadcast channel resource or common channelresource corresponding to the second actual access resource.

With reference to the second aspect or any of the first to fourthpossible implementation manners of the second aspect, in a fifthpossible implementation manner, after the sending the synchronizationsignal on the actual access resource by using the actual sequence, themethod further includes: sending a second reference signal at theresource location of the actual access resource, where the secondreference signal is a reference signal segment clipped from a firstreference signal and corresponding to the resource location, and thefirst reference signal is a reference signal generated by using a centerfrequency point of the current cell as a center and using a quantity ofresource blocks included in the bandwidth of the current cell as afrequency domain width; or sending a second reference signal at theresource location of the actual access resource, where the secondreference signal is a reference signal segment clipped from a frequencydomain center of a first reference signal and corresponding to a firstfrequency domain width, the first frequency domain width is a frequencydomain width occupied by the actual access resource, a reference signalin the bandwidth of the current cell is a cyclic shift of the firstreference signal, and the first reference signal is a reference signalgenerated by using a center frequency point of the current cell as acenter and using a quantity of resource blocks included in the bandwidthof the current cell as a frequency domain width.

With reference to the second aspect or any of the first to fifthpossible implementation manners of the second aspect , in a sixthpossible implementation manner, a specific implementation of determiningan actual access resource of a current cell is: if the resource locationof the actual access resource is not a frequency domain center locationof the current cell, processing a subcarrier in a center of the actualaccess resource as a virtual direct current subcarrier when determiningdivision of resource blocks in the actual access resource.

According to a third aspect, a cell access resource acquisition methodis provided. The method includes: determining, by user equipment UE, atleast one candidate sequence of a synchronization signal of an accesscell of the UE and multiple candidate access resources of the accesscell; detecting, by the UE, the synchronization signal according to theat least one candidate sequence; receiving, by the UE, a broadcastchannel of the access cell on a broadcast channel resource correspondingto an actual access resource on which the detected synchronizationsignal is located, where the actual access resource is one of themultiple candidate access resources, the broadcast channel carriesresource indication information, and the resource indication informationis used for indicating the actual access resource in the multiplecandidate access resources, or the resource indication information isused for indicating a location relationship between the actual accessresource and a resource on which the access cell is located; anddetermining, by the UE, a resource location of the actual accessresource in the access cell according to the resource indicationinformation.

With reference to the third aspect, in a first possible implementationmanner, when the resource indication information is used for indicatingthe actual access resource in the multiple candidate access resources, acorresponding location relationship exists between each candidate accessresource in the multiple candidate access resources and the resource onwhich the access cell is located, and in this case, a specificimplementation of determining, by the UE, a resource location of theactual access resource in the access cell according to the resourceindication information is: determining, by the UE, the actual accessresource in the multiple candidate access resources according to theresource indication information; and determining, by the UE, theresource location of the actual access resource in the access cellaccording to the corresponding location relationship existing betweeneach candidate access resource in the multiple candidate accessresources and the resource on which the access cell is located.

With reference to the third aspect, in a second possible implementationmanner, when the resource indication information is used for indicatingthe location relationship between the actual access resource and theresource on which the access cell is located, a specific implementationof determining, by the UE, a resource location of the actual accessresource in the access cell according to the resource indicationinformation includes: determining, by the UE, the resource location ofthe actual access resource in the access cell according to the locationrelationship, indicated by the resource indication information, betweenthe actual access resource and the resource on which the access cell islocated.

With reference to the third aspect or any of the first and the secondpossible implementation manners of the third aspect, after thedetermining, by the UE, a resource location of the actual accessresource in the access cell according to the resource indicationinformation, the method further includes: determining, by the UE, a cellidentifier of the access cell according to the resource location of theactual access resource in the access cell and an actual sequence of thedetected synchronization signal.

With reference to the third aspect or any of the first to third possibleimplementation manners of the third aspect, in a fourth possibleimplementation manner, after the determining, by the UE, a resourcelocation of the actual access resource in the access cell according tothe resource indication information, the method further includes: if theactual access resource includes a first actual access resource and asecond actual access resource, acquiring, by the UE, a first randomaccess configuration and a second random access configuration on thefirst actual access resource and the second actual access resource,respectively, where the first random access configuration corresponds tothe first actual access resource, and the second random accessconfiguration corresponds to the second actual access resource.

With reference to the third aspect or any of the first to fourthpossible implementation manners of the third aspect, in a fifth possibleimplementation manner, after the determining, by the UE, a resourcelocation of the actual access resource in the access cell according tothe resource indication information, the method further includes:

determining, by the UE, a second reference signal that is at theresource location of the actual access resource, where the secondreference signal is a reference signal segment clipped from a firstreference signal and corresponding to the resource location, and thefirst reference signal is a reference signal generated by using a centerfrequency point of the access cell as a center and using a quantity ofresource blocks included in a bandwidth of the access cell as afrequency domain width; or determining, by the UE, a second referencesignal that is at the resource location of the actual access resource,where the second reference signal is a reference signal segment clippedfrom a frequency domain center of a first reference signal andcorresponding to a first frequency domain width, the first frequencydomain width is a frequency domain width occupied by the actual accessresource, a reference signal in a bandwidth of the access cell is acyclic shift of the first reference signal, and the first referencesignal is a reference signal generated by using a center frequency pointof the access cell as a center and using a quantity of resource blocksincluded in the bandwidth of the access cell as a frequency domainwidth.

With reference to the third aspect or any of the first to fifth possibleimplementation manners of the third aspect, in a sixth possibleimplementation manner, the method further includes: if the resourcelocation of the actual access resource is not a frequency domain centerlocation of the access cell, processing, by the UE, a subcarrier in acenter of the actual access resource as a virtual direct currentsubcarrier when determining division of resource blocks in the actualaccess resource.

With reference to the sixth possible implementation manner of the thirdaspect, in a seventh possible implementation manner, the broadcastchannel resource corresponding to the actual access resource is aresource on a predefined side of a center frequency point of the actualaccess resource.

According to a fourth aspect, a cell access resource indication methodis provided. The method includes: determining an actual access resourceof a current cell and an actual sequence of a synchronization signal ofthe current cell, where the actual access resource is at least onecandidate access resource in multiple candidate access resources of thecurrent cell, and the actual sequence is one of at least one candidatesequence of the synchronization signal; sending the synchronizationsignal of the current cell on the actual access resource by using theactual sequence; and sending a broadcast channel on a broadcast channelresource corresponding to the actual access resource, where thebroadcast channel carries resource indication information, and theresource indication information is used for indicating the actual accessresource in the multiple candidate access resources, or the resourceindication information is used for indicating a location relationshipbetween the actual access resource and a resource on which the currentcell is located.

With reference to the fourth aspect, in a first possible implementationmanner, a resource location of the actual access resource in the currentcell and the actual sequence of the synchronization signal are furtherused for indicating a cell identifier of the current cell.

With reference to the fourth aspect or the first possible implementationmanner of the fourth aspect, in a second possible implementation manner,after the sending a broadcast channel on a broadcast channel resourcecorresponding to the actual access resource, the method furtherincludes: if the actual access resource includes a first actual accessresource and a second actual access resource, respectively sending afirst random access configuration and a second random accessconfiguration on a broadcast channel resource or common channel resourcecorresponding to the first actual access resource and a broadcastchannel resource or common channel resource corresponding to the secondactual access resource, where the first random access configurationcorresponds to the first actual access resource, and the second randomaccess configuration corresponds to the second actual access resource.

With reference to the fourth aspect or any of the first and the secondpossible implementation manners of the fourth aspect, in a thirdpossible implementation manner, after the sending a broadcast channel ona broadcast channel resource corresponding to the actual accessresource, the method further includes: sending a second reference signalat the resource location of the actual access resource, where the secondreference signal is a reference signal segment clipped from a firstreference signal and corresponding to the resource location, and thefirst reference signal is a reference signal generated by using a centerfrequency point of the current cell as a center and using a quantity ofresource blocks included in a bandwidth of the current cell as afrequency domain width; or sending a second reference signal at theresource location of the actual access resource, where the secondreference signal is a reference signal segment clipped from a frequencydomain center of a first reference signal and corresponding to a firstfrequency domain width, the first frequency domain width is a frequencydomain width occupied by the actual access resource, a reference signalin a bandwidth of the current cell is a cyclic shift of the firstreference signal, and the first reference signal is a reference signalgenerated by using a center frequency point of the current cell as acenter and using a quantity of resource blocks included in the bandwidthof the current cell as a frequency domain width.

With reference to the fourth aspect or any of the first to thirdpossible implementation manners of the fourth aspect, in a fourthpossible implementation manner, a specific implementation of determiningan actual access resource of a current cell is: if the resource locationof the actual access resource is not a frequency domain center locationof the current cell, processing a subcarrier in a center of the actualaccess resource as a virtual direct current subcarrier when determiningdivision of resource blocks in the actual access resource.

With reference to the fourth possible implementation manner of thefourth aspect, in a fifth possible implementation manner, the broadcastchannel resource corresponding to the actual access resource is aresource on a predefined side of a center frequency point of the actualaccess resource.

According to a fifth aspect, user equipment is provided. The userequipment includes: a determining unit, configured to determine at leastone candidate sequence of a synchronization signal of an access cell ofthe user equipment and multiple candidate access resources of the accesscell, where a corresponding location relationship exists between eachcandidate access resource in the multiple candidate access resources anda resource on which the access cell is located, and any candidatesequence in the at least one candidate sequence corresponds to one ofthe multiple candidate access resources; and a detecting unit,configured to detect the synchronization signal according to the atleast one candidate sequence, where the determining unit is furtherconfigured to determine a resource location of an actual access resourcecorresponding to a detected actual sequence in the access cell accordingto the location relationship between each candidate access resource inthe multiple candidate access resources and the resource on which theaccess cell is located and a correspondence between the any candidatesequence in the at least one candidate sequence and the multiplecandidate access resources, where the actual sequence is one of the atleast one candidate sequence, and the actual access resource is one ofthe multiple candidate access resources.

With reference to the fifth aspect, in a first possible implementationmanner, when configured to determine the resource location of the actualaccess resource corresponding to the detected actual sequence in theaccess cell according to the location relationship between eachcandidate access resource in the multiple candidate access resources andthe resource on which the access cell is located and a correspondencebetween the any candidate sequence in the at least one candidatesequence and the multiple candidate access resources, the determiningunit is specifically configured to: determine the actual access resourcecorresponding to the actual sequence from the multiple candidate accessresources; and determine the resource location of the actual accessresource in the access cell according to the location relationshipbetween the multiple candidate access resources and the resource onwhich the access cell is located.

With reference to the fifth aspect or the first possible implementationmanner of the fifth aspect, in a second possible implementation manner,the candidate sequence is a complete sequence; or the candidate sequenceis a segmental sequence in a complete sequence.

With reference to the fifth aspect or any of the first and the secondpossible implementation manners of the fifth aspect, in a third possibleimplementation manner, besides a first candidate access resource, atleast one candidate access resource exists in the multiple candidateaccess resources, the first candidate access resource is a resourcehaving a frequency domain width of N resource blocks in a center of theaccess cell, and N is a preconfigured natural number.

With reference to the fifth aspect or any of the first to third possibleimplementation manners of the fifth aspect, in a fourth possibleimplementation manner, the determining unit is further configured todetermine a location of a center frequency point of the access cellaccording to the resource location of the actual access resource in theaccess cell.

With reference to the fifth aspect or any of the first to fourthpossible implementation manners of the fifth aspect, in a fifth possibleimplementation manner, the user equipment further includes a receivingunit, configured to receive a broadcast channel of the access cell,where the broadcast channel carries bandwidth indication information ofthe access cell, where the determining unit is further configured todetermine a bandwidth of the access cell according to the bandwidthindication information.

With reference to the fifth aspect or any of the first to fourthpossible implementation manners of the fifth aspect, in a sixth possibleimplementation manner, the user equipment further includes a receivingunit, configured to: if the actual access resource includes a firstactual access resource and a second actual access resource, acquire afirst random access configuration and a second random accessconfiguration on the first actual access resource and the second actualaccess resource, respectively, where the first random accessconfiguration corresponds to the first actual access resource, and thesecond random access configuration corresponds to the second actualaccess resource.

With reference to the fifth aspect or any of the first to sixth possibleimplementation manners of the fifth aspect, in a seventh possibleimplementation manner, the determining unit is further configured todetermine a second reference signal that is at the resource location ofthe actual access resource, where the second reference signal is areference signal segment clipped from a first reference signal andcorresponding to the resource location, and the first reference signalis a reference signal generated by using the center frequency point ofthe access cell as a center and using a quantity of resource blocksincluded in the bandwidth of the access cell as a frequency domainwidth; or the second reference signal is a reference signal segmentclipped from a frequency domain center of a first reference signal andcorresponding to a first frequency domain width, the first frequencydomain width is a frequency domain width occupied by the actual accessresource, a reference signal in the bandwidth of the access cell is acyclic shift of the first reference signal, and the first referencesignal is a reference signal generated by using the center frequencypoint of the access cell as a center and using a quantity of resourceblocks included in the bandwidth of the access cell as a frequencydomain width.

With reference to the fifth aspect or any of the first to seventhpossible implementation manners of the fifth aspect, in an eighthpossible implementation manner, the determining unit is furtherconfigured to: if the resource location of the actual access resource isnot a frequency domain center location of the access cell, process asubcarrier in a center of the actual access resource as a virtual directcurrent subcarrier when determining division of resource blocks in theactual access resource.

According to a sixth aspect, a base station is provided. The basestation includes: a determining unit, configured to determine an actualaccess resource of a current cell of the base station and an actualsequence of a synchronization signal of the current cell, where theactual access resource is at least one candidate access resource inmultiple candidate access resources used by the current cell to send thesynchronization signal, the actual sequence is one of at least onecandidate sequence of the synchronization signal, and any candidatesequence in the at least one candidate sequence corresponds to one ofthe multiple candidate access resources; and a sending unit, configuredto send the synchronization signal on the actual access resource byusing the actual sequence.

With reference to the sixth aspect, in a first possible implementationmanner, the one of the at least one candidate sequence is a completesequence; or the one of the at least one candidate sequence is asegmental sequence in a complete sequence.

With reference to the sixth aspect or the first possible implementationmanner of the sixth aspect, in a second possible implementation manner,besides a first candidate access resource, at least one candidate accessresource exists in the multiple candidate access resources, the firstcandidate access resource is a resource having a frequency domain widthof N resource blocks in a center of the current cell, and N is apreconfigured natural number.

With reference to the sixth aspect or any of the first and secondpossible implementation manners of the sixth aspect, in a third possibleimplementation manner, the sending unit is further configured to send abroadcast channel in the current cell, where the broadcast channelcarries bandwidth indication information of the current cell, and thebandwidth indication information of the current cell is used forindicating a bandwidth of the current cell.

With reference to the sixth aspect or any of the first to third possibleimplementation manners of the sixth aspect, in a fourth possibleimplementation manner, the sending unit is further configured to: if theactual access resource includes a first actual access resource and asecond actual access resource, send a first random access configurationof the current cell on a broadcast channel resource or common channelresource corresponding to the first actual access resource, and send asecond random access configuration of the current cell on a broadcastchannel resource or common channel resource corresponding to the secondactual access resource.

With reference to the sixth aspect or any of the first to fourthpossible implementation manners of the sixth aspect, in a fifth possibleimplementation manner, the sending unit is further configured to send asecond reference signal at the resource location of the actual accessresource, where the second reference signal is a reference signalsegment clipped from a first reference signal and corresponding to theresource location, and the first reference signal is a reference signalgenerated by using a center frequency point of the current cell as acenter and using a quantity of resource blocks included in the bandwidthof the current cell as a frequency domain width; or the second referencesignal is a reference signal segment clipped from a frequency domaincenter of a first reference signal and corresponding to a firstfrequency domain width, the first frequency domain width is a frequencydomain width occupied by the actual access resource, a reference signalin the bandwidth of the current cell is a cyclic shift of the firstreference signal, and the first reference signal is a reference signalgenerated by using a center frequency point of the current cell as acenter and using a quantity of resource blocks included in the bandwidthof the current cell as a frequency domain width.

With reference to the sixth aspect or any of the first to fifth possibleimplementation manners of the sixth aspect, in a sixth possibleimplementation manner, when configured to determine the actual accessresource of the current cell of the base station, the determining unitis specifically configured to: if the resource location of the actualaccess resource is not a frequency domain center location of the currentcell, process a subcarrier in a center of the actual access resource asa virtual direct current subcarrier when determining division ofresource blocks in the actual access resource.

According to a seventh aspect, user equipment is provided. The userequipment includes: a determining unit, configured to determine at leastone candidate sequence of a synchronization signal of an access cell andmultiple candidate access resources of the access cell; a detectingunit, configured to detect the synchronization signal according to theat least one candidate sequence; and a receiving unit, configured toreceive a broadcast channel of the access cell on a broadcast channelresource corresponding to an actual access resource on which thedetected synchronization signal is located, where the actual accessresource is one of the multiple candidate access resources, thebroadcast channel carries resource indication information, and theresource indication information is used for indicating the actual accessresource in the multiple candidate access resources, or the resourceindication information is used for indicating a location relationshipbetween the actual access resource and a resource on which the accesscell is located, where the determining unit is further configured todetermine a resource location of the actual access resource in theaccess cell according to the resource indication information.

With reference to the seventh aspect, in a first possible implementationmanner, when the resource indication information is used for indicatingthe actual access resource in the multiple candidate access resources, acorresponding location relationship exists between each candidate accessresource in the multiple candidate access resources and the resource onwhich the access cell is located, and in this case, when configured todetermine the resource location of the actual access resource in theaccess cell according to the resource indication information, thedetermining unit is specifically configured to: determine the actualaccess resource in the multiple candidate access resources according tothe resource indication information; and determine the resource locationof the actual access resource in the access cell according to thecorresponding location relationship existing between each candidateaccess resource in the multiple candidate access resources and theresource on which the access cell is located.

With reference to the seventh aspect, in a second possibleimplementation manner, when the resource indication information is usedfor indicating the location relationship between the actual accessresource and the resource on which the access cell is located, whenconfigured to determine the resource location of the actual accessresource in the access cell according to the resource indicationinformation, the determining unit is specifically configured to:determine the resource location of the actual access resource in theaccess cell according to the location relationship, indicated by theresource indication information, between the actual access resource andthe resource on which the access cell is located.

With reference to the seventh aspect or any of the first and secondpossible implementation manners of the seventh aspect, in a thirdpossible implementation manner, the determining unit is furtherconfigured to determine a cell identifier of the access cell accordingto the resource location of the actual access resource in the accesscell and an actual sequence of the detected synchronization signal.

With reference to the seventh aspect or any of the first to thirdpossible implementation manners of the seventh aspect, in a fourthpossible implementation manner, the receiving unit is further configuredto: if the actual access resource includes a first actual accessresource and a second actual access resource, acquire a first randomaccess configuration and a second random access configuration on thefirst actual access resource and the second actual access resource,respectively, where the first random access configuration corresponds tothe first actual access resource, and the second random accessconfiguration corresponds to the second actual access resource.

With reference to the seventh aspect or any of the first to fourthpossible implementation manners of the seventh aspect, in a fifthpossible implementation manner, a the determining unit is furtherconfigured to determine a second reference signal that is at theresource location of the actual access resource, where the secondreference signal is a reference signal segment clipped from a firstreference signal and corresponding to the resource location, and thefirst reference signal is a reference signal generated by using a centerfrequency point of the access cell as a center and using a quantity ofresource blocks included in a bandwidth of the access cell as afrequency domain width; or the second reference signal is a referencesignal segment clipped from a frequency domain center of a firstreference signal and corresponding to a first frequency domain width,the first frequency domain width is a frequency domain width occupied bythe actual access resource, a reference signal in a bandwidth of theaccess cell is a cyclic shift of the first reference signal, and thefirst reference signal is a reference signal generated by using a centerfrequency point of the access cell as a center and using a quantity ofresource blocks included in the bandwidth of the access cell as afrequency domain width.

With reference to the seventh aspect or any of the first to fifthpossible implementation manners of the seventh aspect, in a sixthpossible implementation manner, the determining unit is furtherconfigured to: if the resource location of the actual access resource isnot a frequency domain center location of the access cell, process asubcarrier in a center of the actual access resource as a virtual directcurrent subcarrier when determining division of resource blocks in theactual access resource.

With reference to the sixth possible implementation manner of theseventh aspect, in a seventh possible implementation manner, thebroadcast channel resource corresponding to the actual access resourceis a resource on a predefined side of a center frequency point of theactual access resource.

According to an eighth aspect, a base station is provided. The basestation includes: a determining unit, configured to determine an actualaccess resource of a current cell of the base station and an actualsequence of a synchronization signal of the current cell, where theactual access resource is at least one candidate access resource inmultiple candidate access resources of the current cell, and the actualsequence is one of at least one candidate sequence of thesynchronization signal; and a sending unit, configured to send thesynchronization signal of the current cell on the actual access resourceby using the actual sequence, where the sending unit is furtherconfigured to send a broadcast channel on a broadcast channel resourcecorresponding to the actual access resource, where the broadcast channelcarries resource indication information, and the resource indicationinformation is used for indicating the actual access resource in themultiple candidate access resources, or the resource indicationinformation is used for indicating a location relationship between theactual access resource and a resource on which the current cell islocated.

With reference to the eighth aspect, in a first possible implementationmanner, a resource location of the actual access resource in the currentcell and the actual sequence of the synchronization signal are furtherused for indicating a cell identifier of the current cell.

With reference to the eighth aspect or the first possible implementationmanner of the eighth aspect, in a second possible implementation manner,the sending unit is further configured to: if the actual access resourceincludes a first actual access resource and a second actual accessresource, respectively send a first random access configuration and asecond random access configuration on a broadcast channel resource orcommon channel resource corresponding to the first actual accessresource and a broadcast channel resource or common channel resourcecorresponding to the second actual access resource, where the firstrandom access configuration corresponds to the first actual accessresource, and the second random access configuration corresponds to thesecond actual access resource.

With reference to the eighth aspect or any of the first and secondpossible implementation manners of the eighth aspect, in a thirdpossible implementation manner, the sending unit is further configuredto send a second reference signal at the resource location of the actualaccess resource, where the second reference signal is a reference signalsegment clipped from a first reference signal and corresponding to theresource location, and the first reference signal is a reference signalgenerated by using a center frequency point of the current cell as acenter and using a quantity of resource blocks included in a bandwidthof the current cell as a frequency domain width; or the second referencesignal is a reference signal segment clipped from a frequency domaincenter of a first reference signal and corresponding to a firstfrequency domain width, the first frequency domain width is a frequencydomain width occupied by the actual access resource, a reference signalin a bandwidth of the current cell is a cyclic shift of the firstreference signal, and the first reference signal is a reference signalgenerated by using a center frequency point of the current cell as acenter and using a quantity of resource blocks included in the bandwidthof the current cell as a frequency domain width.

With reference to the eighth aspect or any of the first to thirdpossible implementation manners of the eighth aspect, in a fourthpossible implementation manner, when configured to determine the actualaccess resource of the current cell of the base station, the determiningunit is specifically configured to: if the resource location of theactual access resource is not a frequency domain center location of thecurrent cell, process a subcarrier in a center of the actual accessresource as a virtual direct current subcarrier when determiningdivision of resource blocks in the actual access resource.

With reference to the fourth possible implementation manner of theeighth aspect, in a fifth possible implementation manner, the broadcastchannel resource corresponding to the actual access resource is aresource on a predefined side of a center frequency point of the actualaccess resource.

In the information transmission method, the user equipment, and the basestation in the embodiments of the present application, a resourcelocation of an actual access resource in a resource on which an accesscell is located is determined by using a location relationship between acandidate access resource and the resource on which the access cell islocated and a detected actual sequence of a synchronization signal,which can, to some extent, avoid interference impact caused by intensivecells to access by UE, coordinate inter-cell interference of a commoncontrol channel, and improve performance of detection on the commoncontrol channel.

BRIEF DESCRIPTION OF DRAWINGS

The following briefly introduces the accompanying drawings used indescribing the embodiments.

FIG. 1 is a flowchart of a cell access resource acquisition methodaccording to an embodiment of the present application;

FIG. 2 is a schematic diagram of a location relationship between a cellcarrier and a candidate access resource according to an embodiment ofthe present application;

FIG. 3 is a schematic diagram of a relationship between a referencesignal and a cell carrier according to an embodiment of the presentapplication;

FIG. 4 is a schematic diagram of another relationship between areference signal and a cell carrier according to an embodiment of thepresent application;

FIG. 5 is a schematic diagram of locations of a direct currentsubcarrier in a carrier center and a non-carrier center according to anembodiment of the present application;

FIG. 6 is a schematic diagram of relationships between a candidateaccess resource and a direct current subcarrier in two cases: a carriercenter and a non-carrier center;

FIG. 7 is a flowchart of a cell access resource indication methodaccording to an embodiment of the present application;

FIG. 8 is a flowchart of another cell access resource acquisition methodaccording to an embodiment of the present application;

FIG. 9 is a flowchart of another cell access resource indication methodaccording to an embodiment of the present application;

FIG. 10 is a schematic block diagram of user equipment according to anembodiment of the present application;

FIG. 11 is a schematic block diagram of a base station according to anembodiment of the present application;

FIG. 12 is a schematic block diagram of another user equipment accordingto an embodiment of the present application;

FIG. 13 is a schematic block diagram of another base station accordingto an embodiment of the present application;

FIG. 14 is a simplified structural diagram of still another userequipment according to an embodiment of the present application;

FIG. 15 is a simplified structural diagram of still another base stationaccording to an embodiment of the present application;

FIG. 16 is a simplified structural diagram of still another userequipment according to an embodiment of the present application;

FIG. 17 is a simplified structural diagram of still another base stationaccording to an embodiment of the present application;

FIG. 18 is a schematic diagram of a method for determining a sequence ofa reference signal according to an embodiment of the presentapplication; and

FIG. 19 is a schematic diagram of another method for determining asequence of a reference signal according to an embodiment of the presentapplication.

DESCRIPTION OF EMBODIMENTS

The technical solutions of the present application may be applied tovarious communications systems, such as Global System for MobileCommunications (GSM), Code Division Multiple Access (CDMA) system,Wideband Code Division Multiple Access (WCDMA) system, general packetradio service (GPRS), and Long Term Evolution (LTE) system.

User equipment (UE) may communicate with one or more core networks byusing a radio access network (RAN). The user equipment may be a mobileterminal, such as a mobile phone (also referred to as a “cellular”phone) or a computer with a mobile terminal. For example, the userequipment may be a portable, pocket-sized, handheld, computer built-in,or in-vehicle mobile apparatus, which exchanges voice and/or data withthe radio access network.

A base station may be a base transceiver station (BTS) in GSM or CDMA,may be a NodeB in WCDMA, or may be an evolved NodeB (eNB or e-NodeB) inLTE. The type of the base station is not limited in the presentapplication. For ease of description, the following embodiments aredescribed by using an eNB as an example.

FIG. 1 is a flowchart of a method for acquiring a cell access resourceaccording to an embodiment of the present application. The method isexecuted by a user equipment device (referred to as UE hereinafter).

101: The UE determines at least one candidate sequence of asynchronization signal of an access cell of the UE, and multiplecandidate access resources of the access cell.

A corresponding location relationship exists between each candidateaccess resource and a resource on which the access cell is located, andany candidate sequence in the at least one candidate sequencecorresponds to one of the multiple candidate access resources.

In this embodiment of the present application, a relative locationrelationship between a candidate access resource and the resource onwhich the access cell is located may be a frequency interval between aresource location of the candidate access resource and a location of acenter frequency point of the access cell, or a frequency intervalbetween a resource location of the candidate access resource and alocation of a low frequency of the access cell, or a frequency intervalbetween a resource location of the candidate access resource and alocation of a high frequency of the access cell.

102: The UE detects the synchronization signal according to the at leastone candidate sequence.

103: The UE determines a resource location of an actual access resourcecorresponding to a detected actual sequence in the access cell accordingto the location relationship between each candidate access resource inthe multiple candidate access resources and the resource on which theaccess cell is located and a correspondence between the any candidatesequence in the at least one candidate sequence and the multiplecandidate access resources.

The actual sequence is one of the at least one candidate sequence, andthe actual access resource is one of the multiple candidate accessresources.

In this embodiment of the present application, a resource location of anactual access resource in a resource on which an access cell is locatedis determined by using a location relationship between a candidateaccess resource and the resource on which the access cell is located anda detected actual sequence of a synchronization signal, which can, tosome extent, avoid interference impact caused by intensive cells toaccess by UE, coordinate inter-cell interference of a common controlchannel, and improve performance of detection on the common controlchannel.

In addition, the actual access resource is determined by detecting thesequence of the synchronization signal. Because detection on thesynchronization signal is the first step for the UE to discover acarrier, the UE can determine an access resource earliest, and detectanother signal, such as a reference signal for measurement, on theresource, rather than determine the access resource by further readinganother message such as a broadcast channel, which simplifies steps ofsystem discovery and access, makes it unnecessary to read a broadcastmessage during measurement, and improves time efficiency and powerefficiency.

Optionally, a specific implementation of step 103 may be: determining,by the UE, the actual access resource corresponding to the actualsequence from the multiple candidate access resources; and determining,by the UE, the resource location of the actual access resource in theaccess cell according to the location relationship between the multiplecandidate access resources and the resource on which the access cell islocated.

Optionally, the candidate sequence may be a complete sequence; or thecandidate sequence may be a segmental sequence in a complete sequence.

Optionally, besides a first candidate access resource, at least onecandidate access resource exists in the multiple candidate accessresources. The first candidate access resource is a resource having afrequency domain width of N resource blocks in a center of the accesscell, and N is a preconfigured natural number, for example, N is equalto 6. In addition, N may be specified in a protocol, or specifiedaccording to a policy of an operator.

Optionally, after step 103, the method further includes: determining, bythe UE, the location of the center frequency point of the access cellaccording to the resource location of the actual access resource in theaccess cell.

Optionally, after step 103, the method further includes: receiving, bythe UE, a broadcast channel of the access cell, where the broadcastchannel carries bandwidth indication information of the access cell; anddetermining, by the UE, a bandwidth of the access cell according to thebandwidth indication information.

Optionally, after step 103, the method further includes: if the actualaccess resource includes a first actual access resource and a secondactual access resource, acquiring, by the UE, a first random accessconfiguration and a second random access configuration on the firstactual access resource and the second actual access resource,respectively, where the first random access configuration corresponds tothe first actual access resource, and the second random accessconfiguration corresponds to the second actual access resource.

Optionally, in an embodiment, after step 103, the method furtherincludes: determining, by the UE, a second reference signal that is atthe resource location of the actual access resource. The secondreference signal is a reference signal segment clipped from a firstreference signal and corresponding to the resource location, and thefirst reference signal is a reference signal generated by using thecenter frequency point of the access cell as a center and using aquantity of resource blocks included in the bandwidth of the access cellas a frequency domain width.

Optionally, in an embodiment, after step 103, the method furtherincludes: determining, by the UE, a second reference signal that is atthe resource location of the actual access resource.

The second reference signal is a reference signal segment clipped from afrequency domain center of a first reference signal and corresponding toa first frequency domain width, the first frequency domain width is afrequency domain width occupied by the actual access resource, areference signal in the bandwidth of the access cell is a cyclic shiftof the first reference signal, and the first reference signal is areference signal generated by using the center frequency point of theaccess cell as a center and using a quantity of resource blocks includedin the bandwidth of the access cell as a frequency domain width.

Optionally, after step 103, the method further includes: if the resourcelocation of the actual access resource is not a frequency domain centerlocation of the access cell, processing, by the UE, a subcarrier in acenter of the actual access resource as a virtual direct currentsubcarrier when analyzing division of resource blocks in the actualaccess resource.

The following describes the method in this embodiment of the presentapplication by using a specific embodiment.

Embodiment 1 of the present application: UE determines a resourcelocation of an actual access resource in a resource on which an accesscell is located according to a location relationship between a candidateaccess resource and the resource on which the access cell is located anda detected actual sequence of a synchronization signal.

First, before detecting the synchronization signal, the UE may firstdetermine at least one candidate sequence of the synchronization signalof the UE and multiple candidate access resources of the access cell.The at least one candidate sequence is a candidate sequence that is usedby the access cell of the UE to send the synchronization signal, themultiple candidate access resources are access resources that may beused by the access cell of the UE, the resource on which the access cellis located refers to an entire carrier resource on which the access cellis located, and a corresponding location relationship exists between themultiple candidate access resources and the resource on which the accesscell is located.

FIG. 2 is a schematic diagram of a location relationship between a cellcarrier and a candidate access resource according to an embodiment ofthe present application. As shown in FIG. 2, when a cell carrierbandwidth is 20 MHz, the cell carrier bandwidth may include fivecandidate access resources: candidate access resources 1 to 5 in total;when a cell carrier bandwidth is 10 MHz, the cell carrier bandwidth mayinclude three candidate access resources: candidate access resources 1to 3 in total; when a cell carrier bandwidth is 1.4 MHz, the cellcarrier bandwidth includes only a candidate access resource 1.Certainly, FIG. 2 shows only a possible location relationship between acandidate access resource and a cell carrier, which does not exclude apossibility of another location relationship, for example, when a cellcarrier bandwidth is 10 MHz, nine candidate access resources may beincluded.

An access cell having a 20-MHz carrier bandwidth and including 100resource blocks is used as an example. Assuming that there are fivecandidate access resources in the access cell and each candidate accessresource occupies six resource blocks, corresponding locationrelationships of the five candidate access resources in the 20-MHzcarrier may be preset, for example, there is one candidate accessresource in a carrier center, and two candidate access resources arerespectively included at predefined locations on either side of acarrier center frequency point, as shown by the candidate accessresources 1 to 5 in FIG. 2.

In addition, any candidate sequence in the at least one candidatesequence corresponds to one of the multiple candidate access resources,for example, sequences 1 to 5 correspond to the candidate accessresource 1, and sequences 6 to 10 correspond to the candidate accessresource 2. In this way, the UE detects all the candidate sequences, andif detecting that the actual sequence is the sequence 6, the UE maydetermine, according to the correspondence, that a current actual accessresource is the candidate access resource 2. The candidate sequence maybe a Zadoff-Chu (ZC) sequence, a Gold sequence, an m sequence, or thelike, or may be a segmental sequence clipped from one of the sequences.The candidate sequences, the location relationships of the candidateaccess resources in the carrier, and the correspondences between thecandidate sequences and the candidate access resources are all preset.

A location relationship of a candidate access resource in the resourceon which the access cell is located may be a frequency interval betweena resource location of the candidate access resource and a location of acenter frequency point of the access cell, or a frequency intervalbetween a resource location of the candidate access resource and alocation of a lowest frequency of the access cell, or a frequencyinterval between a resource location of the candidate access resourceand a location of a highest frequency of the access cell, which is notspecifically limited, as long as the location relationship is preset.

Besides a first candidate access resource, the multiple candidate accessresources of the UE may include a candidate access resource. The firstcandidate access resource is a resource having a frequency domain widthof N resource blocks in a center of the access cell, and N is apreconfigured natural number, and may be specified in a protocol, orspecified according to a policy of an operator.

For example, in FIG. 2, in this case, the first candidate accessresource is the candidate access resource 1, and occupies 1.4 MHz, thatis, a frequency domain width of six resource blocks. A specificimplementation in FIG. 2 of that besides the first candidate accessresource, the multiple candidate access resources of the UE include atleast one candidate access resource is: Besides the candidate accessresource 1, the multiple candidate access resources of the UE furtherinclude the candidate access resource 2 to the candidate access resource5. In addition, location relationships of the five candidate accessresources in the entire carrier resource on which the access cell islocated may be specified in a protocol, or specified according to apolicy of an operator.

In this embodiment of the present application, at least one candidateaccess resource of the access cell may be predefined. Specifically, thecandidate access resource may be predefined according to a maximumcarrier bandwidth, and a specific carrier bandwidth may be less than orequal to the maximum carrier bandwidth. For example, each candidateaccess resource may satisfy a condition that a center frequency point ison a 100-KHz grid, to facilitate cell search by the UE, that is,detection on the synchronization signal. For example, in FIG. 2, amaximum carrier bandwidth is 20 MHz and has five candidate accessresources: the candidate access resource 1 to the candidate accessresource 5. If an actual carrier bandwidth is 10 MHz, there are threeactual candidate access resources, but before the UE acquires carrierbandwidth information, the UE can still assume that there are fivecandidate access resources, perform detection on the five candidateaccess resources, and finally determine one or more actual accessresources from three candidate access resources in the middle. That is,a candidate access resource set in the case of a large carrier bandwidthincludes a candidate access resource set in the case of a small carrierbandwidth. In this design manner, detection complexity can besimplified, and compatibility of system designs of different bandwidthscan be retained.

In addition, in this embodiment of the present application, a Zadoff-Chusequence or an m sequence or the like may be used as the candidatesequence. Certainly, a possibility of another sequence is not excluded.Preferably, the Zadoff-Chu sequence may be used as the candidatesequence in this embodiment of the present application. An originalsequence length of the candidate sequence may be less than a sequencelength of a primary synchronization sequence in an LTE release 8.

In an implementation manner of this embodiment of the presentapplication, the candidate sequence may be a sequence whose length is61, so as to distinguish an earlier-release LTE carrier and asubsequently evolved LTE carrier.

In another implementation manner of this embodiment of the presentapplication, the original sequence length of the candidate sequence isequal to the sequence length of the primary synchronization sequence inthe LTE release 8, but an actual length of the candidate sequence isdetermined after puncture of a primary synchronization signal. Forexample, the sequence length of the primary synchronization sequence inthe LTE release 8 is 63, and the candidate sequence in this embodimentof the present application may be a sequence in which a location of asubcarrier at a direct current location in a carrier center ispunctured, whose final sequence length is 62. For another example, twoor more subcarriers may also be punctured for the candidate sequence inthis embodiment of the present application. In this case, a structure ofprimary synchronization signal is consistent with that in an LTE systemin the release 8. To distinguish a carrier type, a candidate sequencespace may be expanded, that is, a quantity of sequences is newlydesigned to distinguish the carrier type, or the carrier type may bedistinguished in another manner, for example, through indication byusing a broadcast channel. A function of carrier type distinguishing inthe foregoing is that a new carrier can use multiple candidate accessresources, while an original carrier type, that is, an earlier-releaseLTE system carrier, has only an access resource in a carrier center.

For example, in FIG. 2, the maximum bandwidth 20 MHz has five candidateaccess resources. Therefore, five different groups of candidatesequences: sequence groups 0 to 4 in total may be used for thesynchronization signal of the access cell, and sequences in the groupsdo not overlap. Candidate sequences of the sequence groups 0 to 4respectively correspond to the candidate access resources 1 to 5, forexample, candidate sequences of the sequence group 0 correspond to thecandidate access resource 1, and candidate sequences of the sequencegroup 1 correspond to the candidate access resource 2. The candidatesequence may be a complete sequence, for example, a ZC sequence whoselength is 61. Alternatively, the candidate sequence may be a sequencesegment in a complete sequence. For example, in FIG. 2, the candidatesequence may be a sequence segment whose length is 61 in a long sequencewhose length is at least 61*5. The long sequence has five sequencesegments whose length is 61, which respectively correspond to thecandidate access resources 1 to 5.

Then, the UE detects the synchronization signal according to the atleast one candidate sequence.

The detecting, by the UE, the synchronization signal according to the atleast one candidate sequence refers to detecting, by the UE, asynchronization signal on the at least one candidate sequence. When theUE detects a synchronization signal and a sequence of thesynchronization signal is one of the at least one candidate sequence, itmay be considered that the UE detects a synchronization signal of theaccess cell, and the detected candidate sequence is an actual sequenceof the synchronization signal of the access cell. Herein, a sequence andan access resource before the sequence of the synchronization signal isdetected are respectively referred to as a candidate sequence and acandidate access resource, the detected sequence of the synchronizationsignal is referred to as an actual sequence, and an access resourcecorresponding to the actual sequence is referred to as an actual accessresource. It can be seen that, the actual sequence is a candidatesequence in multiple candidate sequences, and the actual access resourceis a candidate access resource in the multiple candidate accessresources. It should be noted that, in one access cell, actual sequencesof the access cell may be respectively sent on multiple accessresources, that is, the UE may respectively detect the actual sequenceson the multiple candidate access resources.

Next, the UE determines, according to the detected actual sequence, theactual access resource on which the actual sequence is located.

After the UE detects the synchronization signal, the UE can determineone, corresponding to the actual access resource of the access cell, ofthe multiple candidate access resources of the access cell by using theactual sequence of the synchronization signal. For example, if theactual sequence of the synchronization signal detected by the UE is acandidate sequence in the sequence group 0, the UE may determine thatthe actual access resource of the access cell is the candidate accessresource 1.

Moreover, if multiple actual sequences, for example, an actual sequence1 in the sequence group 0 and an actual sequence 2 in the sequence group1, are detected, the UE may determine, according to the correspondencesbetween the candidate sequences and the candidate access resources, theactual access resource 1 and the actual access resource 2 correspondingto the actual sequence 1 and the actual sequence 2, respectively.

Finally, the UE may determine the resource location of the actual accessresource of the detected actual sequence in the access cell according tothe location relationship between each candidate access resource in themultiple candidate access resources and the resource on which the accesscell is located and a correspondence between the any candidate sequencein the at least one candidate sequence and the multiple candidate accessresources. The actual sequence is one of the at least one candidatesequence, and the actual access resource is one of the multiplecandidate access resources.

A specific implementation of determining the resource location of theactual access resource of the detected actual sequence in the accesscell may be: determining, by the UE, one of the multiple candidateaccess resources that corresponds to the actual sequence; anddetermining, by the UE, the resource location of the actual accessresource in the access cell according to a location relationship betweenthe one of the multiple candidate access resources that corresponds tothe actual sequence and the resource on which the access cell islocated. The determining, by the UE, one of the multiple candidateaccess resources that corresponds to the actual sequence refers to thatthe UE may determine, according to the actual sequence, which one of themultiple candidate access resources of the UE corresponds to the actualaccess resource for sending the actual sequence. Then, the UE maydetermine the resource location of the actual access resource in theaccess cell according to the location relationship between the candidateaccess resource and the resource on which the access cell is located.

Specifically, that the UE may determine, according to the actualsequence, a candidate access resource corresponding to the actual accessresource of the detected actual sequence is that the UE determines theactual access resource is which candidate access resource in themultiple candidate access resources, or determines a location or asequence number of the actual access resource in the multiple candidateaccess resources. In this case, the UE cannot yet obtain a resourcelocation of the actual access resource in an entire carrier on which theaccess cell is located. To acquire the resource location, the resourcelocation of the actual access resource in the access cell needs to befurther determined according to location relationships of the actualaccess resource and the multiple candidate access resources in theresource on which the access cell is located, that is, predefinedlocation relationships. For example, the UE may learn, by using theactual sequence 2, that the actual access resource corresponds to thecandidate access resource 2, and then determine, according to apredefined location relationship of the candidate access resource in thecarrier on which the cell is located, the resource location of theactual access resource in the carrier on which the access cell islocated. Specifically, it can be seen from FIG. 2 that, the candidateaccess resource 2 corresponding to the actual access resource is at thesecond location from the left in the five predefined candidate accessresources, and then it may be determined that the actual access resourceis at the location in the carrier.

Further, the UE may determine a location of a center frequency point ofthe access cell according to the resource location of the actual accessresource in the access cell. After determining that the actual accessresource is at the location in the carrier, the UE may further determinea specific location of the carrier, for example, a location of a centerfrequency point of the carrier.

In addition, after determining the resource location of the actualaccess resource of the detected actual sequence in the access cell, theUE may further determine a bandwidth of the access cell. In animplementation manner of this embodiment of the present application, theUE may receive a broadcast channel of the access cell, acquire, from thebroadcast channel, bandwidth indication information of the access cellcarried by the broadcast channel, and determine the bandwidth of theaccess cell according to the bandwidth indication information. In thiscase, a complete location of the carrier can be totally determined incombination with the determined center frequency point of the carrierand the bandwidth of the carrier acquired from the broadcast channel.

In addition, after determining the resource location of the actualaccess resource of the detected actual sequence in the access cell, theUE may further acquire a random access configuration of the access cell.In this embodiment of the present application, the UE may determinemultiple actual access resources. If the actual access resource includesa first actual access resource and a second actual access resource, theUE acquires a first random access configuration and a second randomaccess configuration on the first actual access resource and the secondactual access resource, respectively. The first random accessconfiguration corresponds to the first actual access resource, and thesecond random access configuration corresponds to the second actualaccess resource. The first random access configuration and the secondrandom access configuration may be uplink random access configurationinformation, including information such as preamble sequences orresource configurations for random access. The UE may receive the firstrandom access configuration on a broadcast channel resource or commonchannel resource corresponding to the first actual access resource, andreceive the second actual access resource on a broadcast channelresource or common channel resource corresponding to the second randomaccess configuration. In this way, it can be ensured that multiple firstaccess resources in one carrier can separately support independentaccess by the UE, which is equivalent to that one carrier has multiplesubsystems. The multiple subsystems may be subsystems in a same standardor release (the standard may be LTE, CDMA, or the like, and the releasemay be an LTE release 8 or release 12 or the like), or may be subsystemsin different standards or different releases. Flexibility of systemmultiplexing is achieved, and a function of balancing access load can befurther implemented.

In addition, after determining the resource location of the actualaccess resource of the detected actual sequence in the access cell, theUE may further determine a second reference signal corresponding to theactual access resource. In this embodiment of the present application, areference signal in the prior art and generated by using the centerfrequency point of the access cell as a center and using a quantity ofresource blocks included in the bandwidth of the access cell as afrequency domain width is referred to as a first reference signal, and areference signal corresponding to the actual access resource is referredto as a second reference signal.

In an implementation manner of this embodiment of the presentapplication, the second reference signal is a reference signal segmentclipped from a first reference signal and corresponding to the resourcelocation, and the first reference signal is a reference signal generatedby using the center frequency point of the access cell as a center andusing a quantity of resource blocks included in the bandwidth of theaccess cell as a frequency domain width. FIG. 3 is a schematic diagramof a relationship between a reference signal and a cell carrieraccording to an embodiment of the present application. As shown in FIG.3, the access cell corresponds to the first reference signal, and theactual access resource corresponds to the second reference signal. Thefirst reference signal is a reference signal generated by using thecenter frequency point of the access cell as a center and using aquantity of resource blocks included in the bandwidth of the access cellas a frequency domain width. A cell carrier corresponding to the firstreference signal is the 20-MHz carrier shown in FIG. 2. Assuming thatthe actual access resource is the candidate access resource 2 in FIG. 2,the second reference signal is a part of reference signal in the firstreference signal and corresponding to the actual access resource. Asshown in FIG. 3, it is assumed that a reference signal in a frequencydomain direction in one candidate access resource includes two numericalpoints (certainly, another numerical point is not excluded, and thedescription herein is merely an example), and the first reference signalis {g, h, c, d, a, b, e, f, i, j}. After determining that the actualaccess resource is the second candidate access resource on the left sidein the carrier of the access cell, and determining the resource locationof the actual access resource in the entire carrier, the UE may clip asecond reference signal {c, d} at the resource location of the actualaccess resource from the first reference signal {g, h, c, d, a, b, e, f,i, j}. In this case, the UE may perform measurement by using the secondreference signal {c, d}. Then, after acquiring bandwidth information ofthe access cell from the broadcast channel, the UE may further acquirethe reference signal that is on the entire carrier of the access cell.

In another implementation manner of this embodiment of the presentapplication, the second reference signal is a reference signal segmentclipped from a frequency domain center of a first reference signal andcorresponding to a first frequency domain width. The first frequencydomain width is a frequency domain width occupied by the actual accessresource. A reference signal in the bandwidth of the access cell is acyclic shift of the first reference signal. The first reference signalis a reference signal generated by using the center frequency point ofthe access cell as a center and using a quantity of resource blocksincluded in the bandwidth of the access cell as a frequency domainwidth.

FIG. 4 is a schematic diagram of a relationship between a referencesignal and a cell carrier according to an embodiment of the presentapplication. As shown in FIG. 4, the access cell corresponds to thefirst reference signal, and the actual access resource corresponds tothe second reference signal. Specifically, a first reference signalbefore a shift may be that shown in FIG. 3. A cell carrier correspondingto the first reference signal is the 20-MHz carrier shown in FIG. 2. Asshown in FIG. 3, it is assumed that a reference signal in a frequencydomain direction in one candidate access resource includes two numericalpoints (certainly, another numerical point is not excluded, and thedescription herein is merely an example),In this case, the firstreference signal may be represented by {g, h, c, d, a, b, e, f, i, j}.Similarly, assuming that the actual access resource is the candidateaccess resource 2 in FIG. 2, after determining that the actual accessresource is the second candidate access resource on the left side in thecarrier of the access cell, and determining the resource location of theactual access resource in the entire carrier, the UE may use referencesignal numerical points {a, b} corresponding to the candidate accessresource and at a center location of the first reference signal {g, h,c, d, a, b, e, f, i, j} before a cyclic shift as the second referencesignal that is at the resource location of the actual access resource.In other words, the UE may use original numerical points at the carriercenter location as numerical points of the second reference signal inthis case. Correspondingly, a first reference signal after a cyclicshift is shown in FIG. 4, and is {c, d, a, b, e, f, i, j, g, h}. In thiscase, measurement may be performed by using the second reference signal{a, b}. Then, after acquiring bandwidth information of the access cellfrom the broadcast channel, the UE may further acquire the referencesignal that is on the entire carrier of the access cell.

In addition, after determining the resource location of the actualaccess resource of the detected actual sequence in the access cell, theUE further needs to determine an available resource in the actual accessresource. If the resource location of the actual access resource is nota frequency domain center location of the access cell, the UE mayprocess a subcarrier in a center of the actual access resource as avirtual direct current subcarrier when determining division of resourceblocks in the actual access resource. In this embodiment of the presentapplication, before receiving the broadcast channel, the UE needs tofirst detect the synchronization signal. If the candidate accessresource carrying the synchronization signal is not in a center of thecarrier, the candidate access resource does not reserve a direct currentsubcarrier. Because the direct current subcarrier is generally at thecenter frequency point of the carrier, if a design structure of asequence of a synchronization signal in the LTE release 8 needs to beretained in this case, that is, a numerical point at a location of thedirect current subcarrier in the center is punctured in a sequence whoselength is of an odd number to obtain a sequence whose length is of aneven number, when the actual access resource is not at the carriercenter location, a subcarrier needs to be reserved at a center frequencypoint of the actual access resource as a virtual direct currentsubcarrier. However, the virtual direct current subcarrier actuallyoccupies a real subcarrier, and the virtual direct current subcarrierdoes not belong to any resource block; as a result, a real directcurrent subcarrier at the carrier center frequency point belongs to aspecial resource block in the carrier center, but the special resourceblock cannot use the real direct current subcarrier.

FIG. 5 is a schematic diagram of locations of a direct currentsubcarrier in a carrier center and a non-carrier center according to anembodiment of the present application. As shown in FIG. 5, an arrow Aindicates a center location of a 20-MHz carrier, and an arrow Bindicates a center location of an actual access resource. In a specialresource block in the carrier center indicated by the arrow A, a directcurrent subcarrier belongs to a specific resource block in the specialresource block. In other words, a candidate access resource at thecarrier center location includes a real direct current subcarrier in thecarrier center, but the resource block is not scheduled for UE becauseof a problem of interference at the direct current subcarrier. Inaddition, it should be understood that, in the actual access resource,not all subcarriers are used for sending a resource, and there may alsobe a null subcarrier. As shown in FIG. 5, assuming that the actualaccess resource is 36 subcarriers on either side of the carrier center,there may be five null subcarriers, and 31 effective subcarriers forsending a resource.

FIG. 6 is a schematic diagram of relationships between a candidateaccess resource and a direct current subcarrier in two cases: a carriercenter and a non-carrier center. In a specific example, resourcedivision structures at a virtual direct current subcarrier and a realdirect current subcarrier are shown in diagrams 6-1 and 6-2 of FIG. 6.In the diagram 6-1 of FIG. 6, the candidate access resource has 5 nullsubcarriers+30 effective subcarriers on the left side, and has 6 nullsubcarriers+30 effective subcarriers on the right side, and onesubcarrier occupied by a virtual direct current location belongs to thecandidate access resource. In the diagram 6-2 of FIG. 6, the candidateaccess resource has 6 null subcarriers+30 effective subcarriers on eachof the left and right sides, and one subcarrier occupied by a directcurrent location does not belong to the candidate access resource. Asshown in the diagram 6-1 of FIG. 6, when the candidate access resourceis not in a carrier center, quantities of subcarriers on the left andright sides of the virtual direct current location are not symmetric,which affects division of resource blocks on one side of the virtualdirect current location, especially when UE detects a synchronizationsignal and the UE cannot yet distinguish whether the location is avirtual direct current location or a real direct current location,causes fuzziness in resource block determining for subsequent broadcastchannel receiving. In an implementation manner of this embodiment of thepresent application, first, the UE determines, by detecting asynchronization signal, a direct current subcarrier location or avirtual direct current subcarrier location in a candidate accessresource on which the synchronization signal is located, but in thiscase, the UE cannot yet distinguish whether it is specifically a directcurrent carrier location or a virtual direct current subcarrierlocation; next, the UE receives a broadcast channel on a frequencydomain side of the direct current subcarrier location or the virtualdirect current subcarrier location in the candidate access resource.Which side is selected may be predefined, which can ensure that surelyan integer quantity of resource blocks are divided or sequenced on theside, and that each resource block still includes 12 subcarriers,avoiding fuzziness in the division of resource blocks and avoidingincluding unequal quantities of subcarriers. For example, in the diagram6-1 of FIG. 6, it may be predefined that the broadcast channel isdetected on the right side of a virtual direct current or direct currentsubcarrier, and it can be seen that there are 36 subcarriers on theright side, which are exactly a frequency domain width of three resourceblocks, and there are three resource blocks on the left side, which areone subcarrier less.

The foregoing method for determining a sequence of a reference signalmay also be implemented independently, without depending on theforegoing embodiment of determining a resource location of an actualaccess resource in an access cell. The following steps are specificallyincluded:

S1: UE detects, by using at least one candidate sequence, asynchronization signal sent by an access cell, and determines an actualsequence of the synchronization signal; and determines an actual accessresource of the access cell according to the determined actual sequenceof the synchronization signal, where the at least one candidate sequenceincludes the actual sequence.

S2: The UE determines a second sequence of a second reference signalthat is on the actual access resource, where a first sequence of thefirst reference signal is generated by using a maximum bandwidth of asingle carrier supported in an LTE system, the second sequence is asecond segmental sequence clipped at a first resource location that isin a center of the first sequence and that has a first frequency domainwidth, and the first frequency domain width is a frequency domain widthof the actual access resource.

S3: The UE communicates with the access cell according to the secondsequence.

Optionally, the actual access resource is not at a frequency domaincenter location of the access cell.

Optionally, a direct current subcarrier that does not belong to anyresource block is independently reserved in a frequency domain center ofthe actual access resource.

Optionally, the UE determines a third sequence of a third referencesignal that is on a reconfiguration resource, where the third sequenceis a third segmental sequence clipped at a second resource location inthe first sequence or a head-to-tail cycle of the first sequence, and alocation shift relationship between the second segmental sequence at thefirst resource location and the third segmental sequence at the secondresource location in the first sequence or the head-to-tail cycle of thefirst sequence is the same as a location shift relationship between thesecond sequence on the actual access resource and the third sequence onthe reconfiguration resource in a carrier of the access cell. Thereconfiguration resource is a resource reconfigured for the UE by anetwork side device, where a frequency domain width of thereconfiguration resource is not greater than a carrier bandwidth of theaccess cell, and the reconfiguration resource and the actual accessresource may overlap or not. Further, the UE communicates with theaccess cell according to the third sequence.

An embodiment of the present application provides user equipment UE,including a processing unit and a communications unit, where

the processing unit is configured to detect, by using at least onecandidate sequence, a synchronization signal sent by an access cell, anddetermine an actual sequence of the synchronization signal; anddetermine an actual access resource of the access cell according to thedetermined actual sequence of the synchronization signal, where the atleast one candidate sequence includes the actual sequence; andconfigured to determine a second sequence of a second reference signalthat is on the actual access resource, where a first sequence of thefirst reference signal is generated by using a maximum bandwidth of asingle carrier supported in an LTE system, the second sequence is asecond segmental sequence clipped at a first resource location that isin a center of the first sequence and that has a first frequency domainwidth, and the first frequency domain width is a frequency domain widthof the actual access resource; and

the communications unit is configured to communicate with the accesscell according to the second sequence.

The processing unit may be a processor. The communications unit may be atransceiver.

The UE is configured to execute the foregoing method, which is notrepeatedly limited.

A specific description is provided by using the following example:

Refer to an embodiment a in FIG. 18 (it is assumed that a maximumbandwidth of a current LTE single carrier is 20 MHz, and a carrierbandwidth of an access cell is 10 MHz):

An actual access resource has a frequency domain width of six resourceblocks in 10 MHz. A first sequence is generated by using the maximumbandwidth 20 MHz, and it is assumed that the first sequence is {k, i, g,e, c, a, b, d, f, h, j, m}. A second sequence is a second segmentalsequence clipped at a first resource location that is in a center of thefirst sequence and that has a frequency domain width of six resourceblocks, and it is assumed that the second segmental sequence is {a, b}.If a second sequence on an actual access resource in the10-MHz-bandwidth carrier of the access cell is {a, b}, the secondsequence is a second segmental sequence clipped at the first resourcelocation that is in the center of the first sequence and that has afrequency domain width of six resource blocks.

UE may detect a synchronization signal on the actual access resource toaccess the cell, where the synchronization signal may be the same as asynchronization signal in a current LTE system, so that backwardcompatible UE can be supported. The actual access resource may be not ata frequency domain center location of the access cell, one directcurrent subcarrier is independently reserved at a center location of theactual access resource, and the subcarrier does not belong to anyresource block, which is similar to reservation of a direct currentsubcarrier at a carrier center location in a conventional LTE system inwhich access is performed from a frequency domain center. After access,the UE may communicate with a network side by using the determinedsecond sequence of a second reference signal that is on the actualaccess resource, for example, perform measurement, synchronization,and/or demodulation by using the second reference signal.

After access, a frequency domain resource may also be reconfigured forthe UE, where the frequency domain resource may be referred to as areconfiguration resource, a frequency domain width of thereconfiguration resource is not greater than the carrier bandwidth ofthe access cell, and the reconfiguration resource and the actual accessresource may overlap or not. For example, a reconfiguration may beperformed for the UE to use the entire 10-MHz bandwidth of the carrierof the access cell, or a reconfiguration may be performed for the UE touse some resources of the 10-MHz bandwidth of the carrier of the accesscell, where the some resources and the actual access resource mayoverlap or not. Alternatively, the foregoing reconfiguration process maybe not implemented by a network side device such as a base station butimplemented by using radio resource control signaling, or the UE mayreceive a broadcast message on the actual access resource or a broadcastchannel resource corresponding to the actual access resource to acquirethe reconfiguration resource; or the UE even may autonomously decide thereconfiguration bandwidth according to a service status of the UE, andthe UE may further report the determined reconfiguration resource to thenetwork side device.

After reconfiguration, the UE needs to determine a third sequence of athird reference signal that is on the reconfiguration resource, wherethe third sequence is a third segmental sequence clipped at a secondresource location in the first sequence, which is specifically shown inFIG. 18. It is assumed that the reconfiguration resource and the actualaccess resource are adjacent but do not overlap, and certainly,overlapping is not excluded. It can be seen that, the third sequence onthe reconfiguration resource is a third segmental sequence {d, f, h}clipped at the second resource location in the first sequence, whereselection of the second resource location needs to satisfy a condition:a location shift relationship between the second segmental sequence atthe first resource location and the third segmental sequence at thesecond resource location in the first sequence is the same as a locationshift relationship between the second sequence on the actual accessresource and the third sequence on the reconfiguration resource in thecarrier of the access cell. Specifically, the location shiftrelationship between the second sequence {a, b} on the actual accessresource in the carrier of the access cell and the third sequence {d, f,h} on the reconfiguration resource in the carrier of the access cell isbeing adjacent, and then the second segmental sequence {a, b} clipped atthe first resource location in the first sequence and the thirdsegmental sequence{d, f, h} clipped at the second resource location inthe first sequence are also kept in the same location shiftrelationship, that is, the sequences of the reference signals on the10-MHz carrier of the access cell are sequence copies clipped from thefirst sequence. After reconfiguration, the UE may communicate with thenetwork side by using the determined third sequence of the thirdreference signal, for example, perform measurement, synchronization,and/or demodulation by using the third reference signal. Refer to anembodiment b in FIG. 19 (it is assumed that a maximum bandwidth of acurrent LTE single carrier is 20 MHz, and a carrier bandwidth of anaccess cell is 15 MHz):

An actual access resource has a frequency domain width of six resourceblocks in 15 MHz. A first sequence is generated by using the maximumbandwidth 20 MHz, and it is assumed that the first sequence is {k, i, g,e, c, a, b, d, f, h, j, m}. A second sequence is a second segmentalsequence clipped at a first resource location that is in a center of thefirst sequence and that has a frequency domain width of six resourceblocks, and it is assumed that the second segmental sequence is {a, b}.If a second sequence on an actual access resource in the15-MHz-bandwidth carrier of the access cell is {a, b}, the secondsequence is a second segmental sequence clipped at the first resourcelocation that is in the center of the first sequence and that has afrequency domain width of six resource blocks.

Synchronization and reconfiguration processes of the UE are the same asthose in the embodiment in FIG. 18, and are not described herein again.

After reconfiguration, the UE needs to determine a third sequence of athird reference signal that is on the reconfiguration resource, wherethe third sequence is a third segmental sequence clipped at a secondresource location in a head-to-tail cycle of the first sequence, whichis specifically shown in FIG. 19. It is assumed that the reconfigurationresource and the actual access resource are adjacent but do not overlap,and certainly, overlapping is not excluded. It can be seen that, thehead-to-tail cycle of the first sequence is {k, i, g, e, c, a, b, d, f,h, j, m, k, i, . . . }, and the third sequence on the reconfigurationresource is a third segmental sequence {h, j, m, k} clipped at thesecond resource location in the head-to-tail cycle of the firstsequence, where selection of the second resource location needs tosatisfy a condition: a location shift relationship between the secondsegmental sequence at the first resource location and the thirdsegmental sequence at the second resource location in the head-to-tailcycle of the first sequence is the same as a location shift relationshipbetween the second sequence on the actual access resource and the thirdsequence on the reconfiguration resource in the carrier of the accesscell. Specifically, the location shift relationship between the secondsequence {a, b} on the actual access resource in the carrier of theaccess cell and the third sequence {h, j, m, k} on the reconfigurationresource in the carrier of the access cell is being adjacent, and thenthe second segmental sequence {a, b} clipped at the first resourcelocation in the head-to-tail cycle of the first sequence and the thirdsegmental sequence{h, j, m, k} clipped at the second resource locationin the cyclic shift of the first sequence are also kept in the samelocation shift relationship, that is, the sequences of the referencesignals on the 15-MHz carrier of the access cell are sequence copiesclipped from the head-to-tail cycle of the first sequence. Afterreconfiguration, the UE may communicate with the network side by usingthe determined third sequence of the third reference signal, forexample, perform measurement, synchronization, and/or demodulation byusing the third reference signal.

In the foregoing embodiments, it can be ensured that backwardcompatibility is supported; a sequence of a synchronization signaland/or a manner of mapping a broadcast channel does not need to bemodified, and implementation complexity is low; and UE is not requiredto perform access from a carrier center, which can coordinate inter-cellinterference, and can further support a non-standard LTE bandwidth, forexample, a 7-MHz or 8-MHz bandwidth, where the current LTE supports onlysix standard bandwidths, that is, 1.4, 3, 5, 10, 15, and 20 MHz.

The previously described UE may also be configured to execute theforegoing method, which is not repeatedly limited. The foregoing methodmay also be used on a network side. Specifically:

S1: A base station determines an actual access resource in a carrier ofan access cell, where a second reference signal is included in theactual access resource, a second sequence of the second reference signalis a second segmental sequence clipped at a first resource location thatis in a center of a first sequence and that has a first frequency domainwidth, the first frequency domain width is a frequency domain width ofthe actual access resource, and the first sequence of a first referencesignal is generated by using a maximum bandwidth of a single carriersupported in an LTE system.

S2: The base station determines a third reference signal that is on thecarrier of the access cell, where a third sequence of the thirdreference signal is a third segmental sequence clipped at a secondresource location in the first sequence or a head-to-tail cycle of thefirst sequence, and a location shift relationship between the secondsegmental sequence at the first resource location and the thirdsegmental sequence at the second resource location in the first sequenceor the head-to-tail cycle of the first sequence is the same as alocation shift relationship between the second sequence on the actualaccess resource in the carrier of the access cell and the third sequenceon the carrier of the access cell.

S3: The base station sends the second reference signal and the thirdreference signal on the carrier of the access cell.

Optionally, the actual access resource is not at a frequency domaincenter location of the access cell.

Optionally, a direct current subcarrier that does not belong to anyresource block is independently reserved in a frequency domain center ofthe actual access resource.

The foregoing method may also be used on an apparatus side, for example,a terminal and a base station.

An embodiment of the present application provides a base station,including a processing unit and a sending unit, where

the processing unit is configured to determine an actual access resourcein a carrier of an access cell, where a second reference signal isincluded in the actual access resource, a second sequence of the secondreference signal is a second segmental sequence clipped at a firstresource location that is in a center of a first sequence and that has afirst frequency domain width, the first frequency domain width is afrequency domain width of the actual access resource, and the firstsequence of a first reference signal is generated by using a maximumbandwidth of a single carrier supported in an LTE system; and configuredto determine a third reference signal that is on the carrier of theaccess cell, where a third sequence of the third reference signal is athird segmental sequence clipped at a second resource location in thefirst sequence or a head-to-tail cycle of the first sequence, and alocation shift relationship between the second segmental sequence at thefirst resource location and the third segmental sequence at the secondresource location in the first sequence or the head-to-tail cycle of thefirst sequence is the same as a location shift relationship between thesecond sequence on the actual access resource in the carrier of theaccess cell and the third sequence on the carrier of the access cell;and

the sending unit is configured to send the second reference signal andthe third reference signal on the carrier of the access cell.

The processing unit may be a processor. The sending unit may be atransmitter.

The base station is configured to execute the foregoing method, which isnot repeatedly limited. The foregoing method for determining a sequenceof a reference signal may also be implemented independently according tothe following embodiment, without depending on the foregoing embodimentof determining a resource location of an actual access resource in anaccess cell. A sequence in this embodiment is a sequence of a referencesignal. The following steps are specifically included:

S1: UE determines a fourth sequence, where the fourth sequence is asequence clipped from a fifth sequence and at a location correspondingto a resource of a transmission bandwidth of the UE, and the fifthsequence is generated by using a maximum bandwidth of a single carriersupported in an LTE system, or the fifth sequence is obtained through acyclic shift or a head-to-tail cycle of a sequence generated by using amaximum bandwidth of a single carrier supported in an LTE system.

S2: The UE communicates with a base station according to the fourthsequence.

The fourth sequence is used as a sequence corresponding to a fourthreference signal. The UE receives the fourth reference signal on thetransmission bandwidth. In this way, the UE may perform measurement,synchronization, and/or demodulation by using the fourth referencesignal, to communicate with the base station.

Optionally, the transmission bandwidth is not at a center location of afrequency domain bandwidth of a cell in which the base station servesthe UE. Optionally, the transmission bandwidth is not at a centerlocation of a carrier used by the base station to serve the UE.

Optionally, the fourth sequence is clipped at a third resource locationthat is in a center of the fifth sequence and that has a third frequencydomain width, where the third frequency domain width is a width of thetransmission bandwidth of the UE.

Optionally, the fourth sequence is not a center part of the fifthsequence, or the fourth sequence is clipped at a third resource locationthat is a location determined according to a first shift from a centerof the fifth sequence and that has a third frequency domain width, wherethe third frequency domain width is a width of the transmissionbandwidth of the UE.

Optionally, a width of the transmission bandwidth is less than themaximum bandwidth of the single carrier supported in the LTE system.

Optionally, the UE performs access on a carrier on which thetransmission bandwidth is located or performs access on a carrier otherthan a carrier on which the transmission bandwidth is located.

Optionally, the UE performs access by using the transmission bandwidthor performs access by using a frequency band in a same carrier otherthan the transmission bandwidth. A resource of a carrier on which thefourth sequence used by the UE in access is located is an actual accessresource of the UE.

The transmission bandwidth of the UE and the actual access resource ofthe UE may overlap or not overlap.

Optionally, the first shift is a shift of a center of the transmissionbandwidth of the UE relative to a frequency point corresponding to acenter of the fifth sequence; or the first shift is a shift of asequence center corresponding to the transmission bandwidth of the UErelative to a center of the fifth sequence.

The transmission bandwidth may be acquired by the UE by using signalingof a network side device such as the base station, for example, acquiredby using radio resource control signaling, or may be acquired by the UEby receiving a broadcast message on the actual access resource or abroadcast channel resource corresponding to the actual access resource,or the UE may autonomously decide the transmission bandwidth accordingto a service status of the UE. The UE may further report the determinedtransmission bandwidth to the network side device. The UE may determinethe first shift by using a location relationship between thetransmission bandwidth and the access resource.

Alternatively, the first shift may be acquired by the UE by usingsignaling of the network side device such as the base station, forexample, acquired by using radio resource control signaling, or may beacquired by the UE by receiving a broadcast message on the actual accessresource or the broadcast channel resource corresponding to the actualaccess resource, or the UE may autonomously decide the first shiftaccording to a service status of the UE. The UE may further report thedetermined first shift to the network side device.

Optionally, the actual access resource is not at a frequency domaincenter location of the cell in which the base station serves the UE.Certainly, optionally, it is not excluded that the actual accessresource may also be at the frequency domain center location of the cellin which the base station serves the UE.

Optionally, a direct current subcarrier that does not belong to anyresource block is independently reserved in a frequency domain center ofthe actual access resource.

Optionally, a direct current subcarrier that does not belong to anyresource block is independently reserved in a frequency domain center ofthe transmission bandwidth.

An example is provided in the following. It is assumed that a maximumbandwidth of a current LTE single carrier is 20 MHz, and the fifthsequence is generated by using 20 MHz. It is assumed that the fifthsequence is {k, i, g, e, c, a, b, d, f, h, j, m}, and the UE maydetermine a location of the fourth sequence in the fifth sequence and aspecific sequence of the fourth sequence by using the first shift andthe center of the transmission bandwidth of the UE, that is, accordingto the location of the fourth sequence in the fifth sequence, determinethe fourth sequence, for example, {e, c, a, b, d, f} or {d, f, h, j},where a location of the first shift is a shift of a center of the fourthsequence relative to a center of the fifth sequence. Alternatively, thefifth sequence is a cyclic shift of {k, i, g, e, c, a, b, d, f, h, j,m}, for example, {j, m, k, i, g, e, c, a, b, d, f, h}, and the UE maydetermine a location of the fourth sequence in the fifth sequence and aspecific sequence of the fourth sequence, for example, {e, c, a, b, d,f} or {b, d, f, h}, by using the first shift and the center of thetransmission bandwidth of the UE, where a location of the first shift isa shift of a center of the fourth sequence relative to a center of thefifth sequence.

In this design manner, a problem of how to obtain a sequence of areference signal that is on a transmission bandwidth actually used bythe UE, in a case in which UE does not know a size of a bandwidthactually used by a base station and the base station generates, by meansof continuous generation by using a sequence generator, a sequence of areference signal used on the entire bandwidth actually used by the basestation, is resolved. In this design manner, the bandwidth used by thebase station and the bandwidth used by the UE may be decoupled, and asequence of a reference signal used on the entire bandwidth actuallyused by the base station may be generated by means of continuousgeneration by using a sequence generator. In this design manner,sequence generation complexity can be simplified, and compatibility ofsystem designs of different bandwidths can be retained. Moreover, the UEmay be further allowed to use some of the bandwidth actually used by thebase station, and the bandwidth actually used by the base station may bea standard LTE bandwidth or a non-standard LTE bandwidth, for example,may be or not be only six standard bandwidths supported by the currentLTE, that is, 1.4, 3, 5, 10, 15, and 20 MHz.

An embodiment of the present application provides user equipment UE,including a processing unit and a communications unit, where

the processing unit is configured to determine a fourth sequence, wherethe fourth sequence is a sequence clipped from a fifth sequence and at alocation corresponding to a resource of a transmission bandwidth of theUE, and the fifth sequence is generated by using a maximum bandwidth ofa single carrier supported in an LTE system, or the fifth sequence isobtained through a cyclic shift or a head-to-tail cycle of a sequencegenerated by using a maximum bandwidth of a single carrier supported inan LTE system; and

the communications unit is configured to communicate with a base stationaccording to the fourth sequence.

The processing unit may be a processor. The communications unit may be atransceiver.

The UE is configured to execute the foregoing method, which is notrepeatedly limited.

The foregoing method may also be used on a network side, and isconsistent with the method on a UE side. Specifically:

S1: A base station determines a fourth sequence, where the fourthsequence is a sequence clipped from a fifth sequence and at a locationcorresponding to a resource of a transmission bandwidth of the UE, andthe fifth sequence is generated by using a maximum bandwidth of a singlecarrier supported in an LTE system, or is obtained through a cyclicshift or a head-to-tail cycle of a sequence generated by using a maximumbandwidth of a single carrier supported in an LTE system.

S2: The base station communicates with UE according to the fourthsequence.

The fourth sequence is used as a sequence corresponding to a fourthreference signal. The base station sends the fourth reference signal onthe transmission bandwidth. In this way, the UE may perform measurement,synchronization, and/or demodulation by using the fourth referencesignal, and the base station may communicate with the UE.

The method on the network side is consistent with that on the UE side,and details are not described again.

An embodiment of the present application provides a base station,including a processing unit and a communications unit, where

the processing unit is configured to determine a fourth sequence, wherethe fourth sequence is a sequence clipped from a fifth sequence and at alocation corresponding to a resource of a transmission bandwidth of theUE, and the fifth sequence is generated by using a maximum bandwidth ofa single carrier supported in an LTE system, or is obtained through acyclic shift or a head-to-tail cycle of a sequence generated by using amaximum bandwidth of a single carrier supported in an LTE system; and

the communications unit is configured to communicate with UE accordingto the fourth sequence.

The processing unit may be a processor. The communications unit may be atransceiver.

The base station is configured to execute the foregoing method, which isnot repeatedly limited.

FIG. 7 is a flowchart of a cell access resource indication methodaccording to an embodiment of the present application. The method inFIG. 7 is executed by a base station.

701: Determine an actual access resource of a current cell and an actualsequence of a synchronization signal of the current cell.

The actual access resource is at least one candidate access resource inmultiple candidate access resources used by the current cell to send thesynchronization signal, the actual sequence is one of at least onecandidate sequence of the synchronization signal, and any candidatesequence in the at least one candidate sequence corresponds to one ofthe multiple candidate access resources.

702: Send the synchronization signal on the actual access resource byusing the actual sequence.

In this embodiment of the present application, a synchronization signalis sent on an actual access resource according to a correspondencebetween a sequence for sending the synchronization signal and acandidate access resource of the synchronization signal by using anactual sequence, so that UE can determine a resource location of theactual access resource in a current cell according to the actualsequence, the actual access resource, and a relative locationrelationship between a candidate access resource indicated by the actualsequence and the current cell, which can, to some extent, avoidinterference impact caused by intensive cells to access by the UE whenthe UE accesses the current cell, coordinate inter-cell interference ofa common control channel, and improve performance of detection on thecommon control channel.

Optionally, the one of the at least one candidate sequence is a completesequence; or the one of the at least one candidate sequence is asegmental sequence in a complete sequence.

Optionally, besides a first candidate access resource, at least onecandidate access resource exists in the multiple candidate accessresources. The first candidate access resource is a resource having afrequency domain width of N resource blocks in a center of the currentcell, and N is a preconfigured natural number. In addition, N may bespecified in a protocol, or specified according to a policy of anoperator.

Optionally, after step 702, the method further includes: sending abroadcast channel in the current cell. The broadcast channel carriesbandwidth indication information of the current cell, and the bandwidthindication information of the current cell is used for indicating abandwidth of the current cell.

Optionally, after the sending the synchronization signal on the actualaccess resource by using the actual sequence, the method furtherincludes: if the actual access resource includes a first actual accessresource and a second actual access resource, sending a first randomaccess configuration of the current cell on the first actual accessresource, and sending a second random access configuration of thecurrent cell on the second actual access resource.

Optionally, after step 702, the method further includes: if the actualaccess resource includes a first actual access resource and a secondactual access resource, sending a first random access configuration ofthe current cell on a broadcast channel resource or common channelresource corresponding to the first actual access resource, and sendinga second random access configuration of the current cell on a broadcastchannel resource or common channel resource corresponding to the secondactual access resource.

Optionally, after step 702, the method further includes: sending asecond reference signal at the resource location of the actual accessresource. The second reference signal is a reference signal segmentclipped from a first reference signal and corresponding to the resourcelocation, and the first reference signal is a reference signal generatedby using a center frequency point of the current cell as a center andusing a quantity of resource blocks included in the bandwidth of thecurrent cell as a frequency domain width.

Optionally, in another embodiment, after step 702, the method furtherincludes: sending a second reference signal at the resource location ofthe actual access resource. The second reference signal is a referencesignal segment clipped from a frequency domain center of a firstreference signal and corresponding to a first frequency domain width,the first frequency domain width is a frequency domain width occupied bythe actual access resource, a reference signal in the bandwidth of thecurrent cell is a cyclic shift of the first reference signal, and thefirst reference signal is a reference signal generated by using a centerfrequency point of the current cell as a center and using a quantity ofresource blocks included in the bandwidth of the current cell as afrequency domain width.

Optionally, a specific implementation of step 701 is: if the resourcelocation of the actual access resource is not a frequency domain centerlocation of the current cell, processing a subcarrier in a center of theactual access resource as a virtual direct current subcarrier whenanalyzing division of resource blocks in the actual access resource.

The following describes the method in this embodiment of the presentapplication by using a specific embodiment.

Embodiment 2 of the present application: A sequence for a base stationto send a synchronization signal can indicate a resource locationrelationship between a resource for sending the synchronization signaland a resource on which a current cell is located. The base stationsends the synchronization signal on an actual access resource by usingan actual sequence, so that on the premise that UE can parse out thesynchronization signal, the UE avoids interference impact caused byintensive cells to access by the UE.

First, the base station may first determine the actual access resourceand the actual sequence of the synchronization signal.

There may be multiple candidate access resources and multiple candidatesequences in the current cell of the base station. A candidate accessresource is an access resource that may be used when the synchronizationsignal is sent, a candidate sequence is a sequence that may be used whenthe synchronization signal is sent, and each candidate sequence in themultiple candidate sequences corresponds to one of the multiplecandidate access resources.

FIG. 2 is a schematic diagram of a relationship between a cell carrierand a candidate access resource according to an embodiment of thepresent application. As shown in FIG. 2, when a cell carrier bandwidthis 20 MHz, the cell carrier bandwidth may include five candidate accessresources: candidate access resources 1 to 5 in total; when a cellcarrier bandwidth is 10 MHz, the cell carrier bandwidth may includethree candidate access resources: candidate access resources 1 to 3 intotal; when a cell carrier bandwidth is 1.4 MHz, the cell carrierbandwidth includes only a candidate access resource 1. Certainly, FIG. 2shows only a possible relationship between a candidate access resourceand a cell carrier, and there may be another possible relationship, forexample, when a cell carrier bandwidth is 10 MHz, the cell carrierbandwidth may include nine candidate access resources.

Besides a first candidate access resource, the multiple candidate accessresources of the base station may include a candidate access resource.The first candidate access resource is a resource having a frequencydomain width of N resource blocks in a center of the current cell, and Nis a preconfigured natural number, and may be specified in a protocol,or specified according to a policy of an operator. For example, in FIG.2, the candidate access resource 1 is the first candidate accessresource, and occupies 1.4 MHz, that is, a frequency domain width of sixresource blocks. Besides the first candidate access resource, themultiple candidate access resources of the base station include at leastone candidate access resource; in FIG. 2, besides the candidate accessresource 1, the multiple candidate access resources of the base stationfurther include the candidate access resource 2 to the candidate accessresource 5. Location relationships of the candidate access resources inan entire carrier resource on which the current cell is located arepreset.

In this embodiment of the present application, at least one candidateaccess resource of the current cell may be predefined, for example,defined according to a maximum carrier bandwidth, and a specific carrierbandwidth may be less than or equal to the maximum carrier bandwidth.For example, each candidate access resource may satisfy a condition thata center frequency point is on a 100-KHz grid, to facilitate cell searchby the UE, that is, detection on the synchronization signal. Forexample, in FIG. 2, a maximum bandwidth is 20 MHz and has five candidateaccess resources: the candidate access resource 1 to the candidateaccess resource 5. If an actual bandwidth is 10 MHz, there are threeactual candidate access resources.

In addition, when determining the actual access resource, the basestation further needs to determine an available resource block in theactual access resource according to a location of the actual accessresource. If the resource location of the actual access resource is nota frequency domain center location of the current cell, the base stationmay process a subcarrier in a center of the actual access resource as avirtual direct current subcarrier when determining division of resourceblocks in the actual access resource. Because the direct currentsubcarrier is generally at a center frequency point of the carrier, ifan original design structure of a sequence of a synchronization signalneeds to be retained in this case, that is, a numerical point at alocation of the direct current subcarrier in the center is punctured ina sequence whose length is of an odd number to obtain a sequence whoselength is of an even number, when the actual access resource is not atthe carrier center location, a subcarrier needs to be reserved at acenter frequency point of the actual access resource as a virtual directcurrent subcarrier. However, the virtual direct current subcarrieractually occupies a real subcarrier, and the virtual direct currentsubcarrier does not belong to any resource block; as a result, a realdirect current subcarrier at the carrier center frequency point belongsto a special resource block in the carrier center, but the specialresource block cannot use the real direct current subcarrier.Specifically, as shown in FIG. 5, a subcarrier that is not counted intoany resource block is reserved in a center of the actual access resourcethat is not at the carrier center location, and the subcarrier isreferred to as a virtual direct current subcarrier; and a candidateaccess resource at the carrier center location includes a real directcurrent subcarrier in the carrier center, and the real direct currentsubcarrier needs to be counted into a resource block, but the resourceblock is not scheduled for UE because of a problem of interference atthe direct current subcarrier. In addition, it can be seen from resourcedivision structures at a virtual direct current subcarrier and a realdirect current subcarrier that are shown in diagrams 6-1 and 6-2 of FIG.6 that, quantities of subcarriers on the left and right sides of avirtual direct current location are not symmetric, which affectsdivision of resource blocks on one side of the virtual direct currentlocation, especially when the UE detects the synchronization signal andthe UE cannot yet distinguish whether the location is a virtual directcurrent location or a real direct current location, causes fuzziness inresource block determining for subsequent broadcast channel receiving.Therefore, when sending a broadcast channel, the base station may sendthe broadcast channel by selecting a frequency domain resource on a sameside of the direct current subcarrier location and the virtual directcurrent subcarrier location, so as to ensure that surely an integerquantity of resource blocks are divided or sequenced on the side. Forexample, in the diagram 6-1 of FIG. 6, it may be predefined that thebroadcast channel is sent on the right side of the virtual directcurrent or direct current subcarrier, and it can be seen that there are36 subcarriers on the right side, which are exactly a frequency domainwidth of three resource blocks, and there are three resource blocks onthe left side, which are one subcarrier less.

In an implementation manner of this embodiment of the presentapplication, the base station may first determine the actual accessresource for sending the synchronization signal, and then determine,according to the resource location relationship between the actualaccess resource and the current cell, a candidate sequence correspondingto the resource location relationship as the actual sequence for sendingthe synchronization signal, where the actual sequence is one of themultiple candidate sequences for sending the synchronization signal, andthe actual access resource is one of the multiple candidate accessresources used for sending the synchronization signal.

In another implementation manner of this embodiment of the presentapplication, the base station may first determine the actual sequencefor sending the synchronization signal, and then determine, according toa candidate sequence corresponding to the actual sequence and used forsending the synchronization signal, the actual access resource forsending the synchronization signal, where the actual sequence is one ofthe multiple candidate sequences for sending the synchronization signal,and the actual access resource is one of the multiple candidate accessresources used for sending the synchronization signal.

A current cell having a 20-MHz carrier bandwidth and including 100resource blocks is used as an example. Assuming that there are fivecandidate access resources in the current cell and each candidate accessresource occupies six resource blocks, corresponding locationrelationships of the five candidate access resources in the 20-MHzcarrier may be preset, for example, there is one candidate accessresource in a carrier center, and two candidate access resources arerespectively included at predefined locations on either side of acarrier center frequency point. In addition, any candidate sequence inthe at least one candidate sequence corresponds to one of the multiplecandidate access resources, for example, sequences 1 to 5 correspond tothe candidate access resource 1, and sequences 6 to 10 correspond to thecandidate access resource 2. If the actual access resource selected bythe current cell to send the synchronization signal is 2, the actualsequence selected by the current cell to send the synchronization signalcan only be 6 to 10; or if the actual sequence selected by the currentcell to send the synchronization signal is 6, the actual access resourceselected by the current cell to send the synchronization signal can onlybe the candidate access resource 2.

In addition, the candidate sequence may be a complete sequence; or thecandidate sequence may be a segmental sequence in a complete sequence.

In this embodiment of the present application, the candidate sequencemay be a Zadoff-Chu sequence or an m sequence. Certainly, a possibilityof another sequence is not excluded. Preferably, the candidate sequencein this embodiment of the present application may be a Zadoff-Chusequence. An original sequence length of the candidate sequence may beless than a sequence length of a primary synchronization sequence in anLTE release 8. The sequence length of the primary synchronizationsequence in the LTE release 8 is 63, and then a numerical value at alocation of a subcarrier at a direct current location in a carriercenter is punctured to use a final sequence whose sequence length is 62.

In an implementation manner of this embodiment of the presentapplication, on the carrier of the present application, the primarysynchronization sequence may be a sequence whose length is 61, which candistinguish an earlier-release LTE carrier and a subsequently evolvedLTE carrier.

In another implementation manner of this embodiment of the presentapplication, the original sequence length of the candidate sequence isequal to the sequence length of the primary synchronization sequence inthe LTE release 8, but an actual length of the candidate sequence isdetermined after puncture of a primary synchronization signal, forexample, two or three subcarriers are punctured.

In this case, a structure of primary synchronization signal isconsistent with that in an LTE system in the release 8. To distinguish acarrier type, a candidate sequence space may be expanded, that is, aquantity of sequences is newly designed to distinguish the carrier type,or the carrier type may be distinguished in another manner, for example,through indication by using a broadcast channel. A function of carriertype distinguishing in the foregoing is that a new carrier can usemultiple candidate access resources, while an original carrier type,that is, an earlier-release LTE system carrier, has only a resource in acarrier center.

For example, in FIG. 2, the maximum bandwidth 20 MHz has five candidateaccess resources. Therefore, five different groups of candidatesequences: sequence groups 0 to 4 in total may be used for thesynchronization signal of the access cell, and sequences in the groupsdo not overlap. Candidate sequences of the sequence groups 0 to 4respectively correspond to the candidate access resources 1 to 5, forexample, candidate sequences of the sequence group 0 correspond to thecandidate access resource 1, and candidate sequences of the sequencegroup 1 correspond to the candidate access resource 2. The candidatesequence may be a complete sequence, for example, a ZC sequence whoselength is 61; or the candidate sequence may be a sequence segment in acomplete sequence, for example, in FIG. 2, the candidate sequence may bea sequence segment whose length is 61 in a long sequence whose length isat least 61*5, where the long sequence has five sequence segments whoselength is 61, which respectively correspond to the candidate accessresources 1 to 5.

The multiple candidate access resources used for sending thesynchronization signal and the multiple candidate sequences for sendingthe synchronization signal may be specified in a protocol, or may bespecified by an operator, or is notified by the base station to the UEby using broadcast signaling. In addition, a candidate sequence for thebase station to send the synchronization signal may be further used forindicating a candidate access resource. Specifically, the candidatesequence may be used for indicating an identifier of the candidateaccess resource or a resource location relationship between thecandidate access resource and the resource on which the current cell islocated.

Then the synchronization signal is sent on the actual access resource byusing the actual sequence.

After selecting the actual sequence and the actual access resource, thebase station may send the synchronization signal.

In addition, after sending the synchronization signal on the actualaccess resource by using the actual sequence, the base station mayfurther send a broadcast channel in the current cell. The broadcastchannel carries bandwidth indication information of the current cell,and the bandwidth indication information of the current cell is used forindicating a bandwidth of the current cell.

For example, in the embodiment shown in FIG. 2, after sending thesynchronization signal on the candidate access resource 2 by using thecandidate sequence 1, the base station may further send a broadcastchannel in the current cell, where the broadcast channel carriesbandwidth indication information of the current cell, for example, 20 Mor a bandwidth indication code representing 20 M.

In addition, after sending the synchronization signal on the actualaccess resource by using the actual sequence, the base station mayfurther send different random configuration information according todifferent actual access resources. For example, assuming that the basestation sends the synchronization signal of the current cell on each ofthe candidate access resource 1 and the candidate access resource 2shown in FIG. 2, the base station may send first random configurationinformation on a broadcast channel resource or common channel resourcecorresponding to the candidate access resource 1, and send second randomconfiguration information on a broadcast channel resource or commonchannel resource corresponding to the candidate access resource 2. Inthis way, the UE may distinguish different random configurationinformation according to different access resource locations of thereceived random configuration information.

In addition, after sending the synchronization signal on the actualaccess resource by using the actual sequence, the base station mayfurther send a second reference signal at the resource location of theactual access resource.

In an implementation manner of this embodiment of the presentapplication, the second reference signal is a reference signal segmentclipped from a first reference signal and corresponding to the resourcelocation, and the first reference signal is a reference signal generatedby using the center frequency point of the current cell as a center andusing a quantity of resource blocks included in the bandwidth of thecurrent cell as a frequency domain width. For example, in FIG. 3, thebase station may send the first reference signal on the entire cellresource of the current cell, where the second reference signalcorresponding to the actual access resource is a part of referencesignal in the first reference signal and corresponding to the actualaccess resource.

In another implementation manner of this embodiment of the presentapplication, the second reference signal is a reference signal segmentclipped from a frequency domain center of a first reference signal andcorresponding to a first frequency domain width, the first frequencydomain width is a frequency domain width occupied by the actual accessresource, a reference signal in the bandwidth of the current cell is acyclic shift of the first reference signal, and the first referencesignal is a reference signal generated by using the center frequencypoint of the current cell as a center and using a quantity of resourceblocks included in the bandwidth of the current cell as a frequencydomain width. For example, in FIG. 3 and FIG. 4, a first referencesignal shown in FIG. 3 is a reference signal sent by the base stationwhen the actual access resource is at the center frequency point of thecurrent cell, a first reference signal shown in FIG. 4 is a referencesignal sent by the base station when the actual access resource is notat the center frequency point of the current cell, a second referencesignal in the first reference signal in FIG. 4 and corresponding to theactual access resource is the same as a reference signal correspondingto an access resource on which the center frequency point is located inFIG. 3, and the first reference signal in FIG. 4 is obtained through acyclic shift of the first reference signal in FIG. 3.

FIG. 8 is a flowchart of another cell access resource acquisition methodaccording to an embodiment of the present application. The method inFIG. 8 is executed by UE.

801: The UE determines at least one candidate sequence of asynchronization signal of an access cell and multiple candidate accessresources of the access cell.

802: The UE detects the synchronization signal according to the at leastone candidate sequence.

803: The UE receives a broadcast channel of the access cell on abroadcast channel resource corresponding to an actual access resource onwhich the detected synchronization signal is located.

The actual access resource is one of the multiple candidate accessresources, the broadcast channel carries resource indicationinformation, and the resource indication information is used forindicating the actual access resource in the multiple candidate accessresources, or the resource indication information is used for indicatinga location relationship between the actual access resource and aresource on which the access cell is located.

804: The UE determines a resource location of the actual access resourcein the access cell according to the resource indication information.

In this embodiment of the present application, a resource location of anactual access resource in an access cell is determined by using theactual access resource of a detected synchronization signal and resourceindication information received on a broadcast channel, which can, tosome extent, avoid interference impact caused by intensive cells toaccess by UE, coordinate inter-cell interference of a common controlchannel, and improve performance of detection on the common controlchannel.

Optionally, in an embodiment, when the resource indication informationis used for indicating the actual access resource in the multiplecandidate access resources, a corresponding location relationship existsbetween each candidate access resource in the multiple candidate accessresources and the resource on which the access cell is located, and aspecific implementation of step 804 may be: determining, by the UE, theactual access resource in the multiple candidate access resourcesaccording to the resource indication information; and determining, bythe UE, the resource location of the actual access resource in theaccess cell according to the corresponding location relationshipexisting between each candidate access resource in the multiplecandidate access resources and the resource on which the access cell islocated.

Optionally, in another embodiment, when the resource indicationinformation is used for indicating the location relationship between theactual access resource and the resource on which the access cell islocated, a specific implementation of step 804 may be: determining, bythe UE, the resource location of the actual access resource in theaccess cell according to the location relationship, indicated by theresource indication information, between the actual access resource andthe resource on which the access cell is located.

Optionally, after step 804, the method further includes: determining, bythe UE, a cell identifier of the access cell according to the resourcelocation of the actual access resource in the access cell and an actualsequence of the detected synchronization signal.

Optionally, after step 804, the method further includes: if the actualaccess resource includes a first actual access resource and a secondactual access resource, acquiring, by the UE, a first random accessconfiguration and a second random access configuration on the firstactual access resource and the second actual access resource,respectively, where the first random access configuration corresponds tothe first actual access resource, and the second random accessconfiguration corresponds to the second actual access resource.

Optionally, in an embodiment, after step 804, the method furtherincludes: determining, by the UE, a second reference signal that is atthe resource location of the actual access resource.

The second reference signal is a reference signal segment clipped from afirst reference signal and corresponding to the resource location, andthe first reference signal is a reference signal generated by using acenter frequency point of the access cell as a center and using aquantity of resource blocks included in a bandwidth of the access cellas a frequency domain width.

Optionally, in another embodiment, after step 804, the method furtherincludes: determining, by the UE, a second reference signal that is atthe resource location of the actual access resource. The secondreference signal is a reference signal segment clipped from a frequencydomain center of a first reference signal and corresponding to a firstfrequency domain width, the first frequency domain width is a frequencydomain width occupied by the actual access resource, a reference signalin a bandwidth of the access cell is a cyclic shift of the firstreference signal, and the first reference signal is a reference signalgenerated by using a center frequency point of the access cell as acenter and using a quantity of resource blocks included in the bandwidthof the access cell as a frequency domain width.

Optionally, after step 804, the method further includes: if the resourcelocation of the actual access resource is not a frequency domain centerlocation of the access cell, processing, by the UE, a subcarrier in acenter of the actual access resource as a virtual direct currentsubcarrier when analyzing division of resource blocks in the actualaccess resource. Further, the broadcast channel resource correspondingto the actual access resource is located on a predefined side of acenter frequency point of the actual access resource.

The following describes the method in this embodiment of the presentapplication by using a specific embodiment.

Embodiment 3 of the present application: UE determines a resourcelocation of an actual access resource in an access cell according to alocation relationship of the actual access resource in a resource onwhich the cell is located and resource indication information in abroadcast channel.

First, before detecting a synchronization signal, the UE may firstdetermine at least one candidate sequence of the synchronization signalof the UE and multiple candidate access resources of the access cell.The at least one candidate sequence is a candidate sequence that is usedby the access cell of the UE to send the synchronization signal, themultiple candidate access resources are access resources that may beused by the access cell of the UE, the resource on which the access cellis located refers to an entire carrier resource on which the access cellis located, and a corresponding location relationship exists betweeneach candidate access resource in the multiple candidate accessresources and the resource on which the access cell is located.

An access cell having a 20-MHz carrier bandwidth and including 100resource blocks is used as an example. Assuming that there are fivecandidate access resources in the access cell and each candidate accessresource occupies six resource blocks, corresponding locationrelationships of the five candidate access resources in the 20-MHzcarrier may be preset, for example, there is one candidate accessresource in a carrier center, and two candidate access resources arerespectively included at predefined locations on either side of acarrier center frequency point.

A location relationship of a candidate access resource in the resourceon which the access cell is located may be a frequency interval betweena resource location of the candidate access resource and a location of acenter frequency point of the access cell, or a frequency intervalbetween a resource location of the candidate access resource and alocation of a lowest frequency of the access cell, or a frequencyinterval between a resource location of the candidate access resourceand a location of a highest frequency of the access cell, which is notspecifically limited, as long as the location relationship is preset.

Besides a first candidate access resource, the multiple candidate accessresources of the UE may include a candidate access resource. The firstcandidate access resource is a resource having a frequency domain widthof N resource blocks in a center of the access cell, and N is apreconfigured natural number, and may be specified in a protocol, orspecified according to a policy of an operator. For example, in FIG. 2,the candidate access resource 1 is the first candidate access resource,and occupies 1.4 MHz, that is, a frequency domain width of six resourceblocks. Besides the first candidate access resource, the multiplecandidate access resources of the UE include at least one candidateaccess resource; in FIG. 2, besides the candidate access resource 1, themultiple candidate access resources of the UE further include thecandidate access resource 2 to the candidate access resource 5. Locationrelationships of the candidate access resources in the entire carrierresource on which the access cell is located are preset.

In this embodiment of the present application, at least one candidateaccess resource of the access cell may be predefined, for example,defined according to a maximum carrier bandwidth, and a specific carrierbandwidth may be less than or equal to the maximum carrier bandwidth.For example, each candidate access resource may satisfy a condition thata center frequency point is on a 100-KHz grid, to facilitate cell searchby the UE, that is, detection on the synchronization signal. Forexample, in FIG. 2, a maximum bandwidth is 20 MHz and has five candidateaccess resources: the candidate access resource 1 to the candidateaccess resource 5. If an actual bandwidth is 10 MHz, there are threeactual candidate access resources, but before the UE acquires bandwidthinformation, the UE can still assume in detection that there are fivecandidate access resources, and finally determine one or more actualaccess resources from three candidate access resources in the middle.That is, a candidate access resource set in a large-bandwidth scenarioincludes a candidate access resource set in a small- bandwidth scenario.In this way, detection complexity can be simplified, and compatibilityof system designs of different bandwidths can be retained.

In this embodiment of the present application, the candidate sequencemay be a Zadoff- Chu sequence or an m sequence. Certainly, a possibilityof another sequence is not excluded. Preferably, the candidate sequencein this embodiment of the present application may be a Zadoff-Chusequence. An original sequence length of the candidate sequence may beless than a sequence length of a primary synchronization sequence in anLTE release 8. The sequence length of the primary synchronizationsequence in the LTE release 8 is 63, and then a numerical value at alocation of a subcarrier at a direct current location in a carriercenter is punctured to use a final sequence whose sequence length is 62.

In an implementation manner of this embodiment of the presentapplication, on the carrier of the present application, the primarysynchronization sequence may be a sequence whose length is 61, which candistinguish an earlier-release LTE carrier and a subsequently evolvedLTE carrier.

In another implementation manner of this embodiment of the presentapplication, the original sequence length of the candidate sequence isequal to the sequence length of the primary synchronization sequence inthe LTE release 8, but an actual length of the candidate sequence isdetermined after puncture of a primary synchronization signal, forexample, two or three subcarriers are punctured.

In this case, a structure of primary synchronization signal isconsistent with that in an LTE system in the release 8. To distinguish acarrier type, a candidate sequence space may be expanded, that is, aquantity of sequences is newly designed to distinguish the carrier type,or the carrier type may be distinguished in another manner, for example,through indication by using a broadcast channel. A function of carriertype distinguishing in the foregoing is that a new carrier can usemultiple candidate access resources, while an original carrier type,that is, an earlier-release LTE system carrier, has only an accessresource in a carrier center.

Then, the UE detects the synchronization signal according to the atleast one candidate sequence.

The UE detects a synchronization signal according to a candidatesequence. When the UE detects a synchronization signal and an actualsequence of the synchronization signal is one of the at least onecandidate sequence, it may be considered that the UE detects thesynchronization signal of the access cell, and the detected candidatesequence is an actual sequence of the synchronization signal of theaccess cell. Moreover, multiple actual sequences may be sent in oneaccess cell, and the multiple actual sequences are respectively sent onthe multiple candidate access resources. In this way, the UE may detectthe multiple actual sequences.

Next, the UE receives a broadcast channel of the access cell on abroadcast channel resource corresponding to an actual access resource onwhich the detected synchronization signal is located.

After the UE detects the synchronization signal, an access resource onwhich the synchronization signal is located is the actual accessresource.

The UE receives a broadcast channel of the access cell on a broadcastchannel resource corresponding to the actual access resource. Thebroadcast channel carries resource indication information, and theresource indication information indicates the actual access resource inthe multiple candidate access resources. The resource indicationinformation may be specifically information that can distinguish acandidate access resource, such as an identifier or a code of thecandidate access resource. For example, the resource indicationinformation is “010”, indicating the candidate access resource 2 in FIG.2, or a relative location relationship of the candidate access resource2 relative to the access cell.

The broadcast channel resource corresponding to the actual accessresource may be understood as that a resource occupied by the broadcastchannel is a subset of the actual access resource, or that a relativelyfixed location relationship exists between a resource on which thebroadcast channel is located and the actual access resource, or thelike, and these correspondences are not limited.

The UE receives the broadcast channel, where the broadcast channel maybe a physical broadcast channel or a physical broadcast channel enhancedin the future, which is not limited. The UE may acquire the resourceindication information carried in the broadcast channel, where theresource indication information may be carried by a bit, a scramblingcode, a time/frequency resource location, or the like in the broadcastchannel, which is not limited herein.

Finally, the UE determines the resource location of the actual accessresource in the access cell according to the corresponding locationrelationship existing between each candidate access resource in themultiple candidate access resources and the resource on which the accesscell is located.

For example, when the UE receives the resource indication information“010”, the UE may determine, according to the actual access resource andthe resource indication information, that the actual access resourcecorresponds to the candidate access resource 2, and further determinethe resource location of the actual access resource in the access cellaccording to the location relationship of the actual access resource inthe resource on which the cell is located.

In addition, the resource indication information may further includebandwidth information of the access cell, and the UE may furtherdetermine a bandwidth of the access cell according to the bandwidthinformation of the access cell in the resource indication information.

In addition, the UE may further determine a cell identifier of theaccess cell according to the resource location of the actual accessresource in the access cell and the sequence of the synchronizationsignal.

In an existing system, after detecting the synchronization signal of thecarrier from the carrier center, the UE may acquire a cell identifier ofthe carrier according to sequence information of the synchronizationsignal, where a value of the cell identifier ranges from 0 to 503. Afterthe multiple candidate access resources are introduced, the value rangeof the cell identifier can be expanded, to adapt to a deploymentscenario of more intensive cells in the future, and resolve a problem ofa cell identifier conflict. For example, the cell identifier of theaccess cell is determined by using the resource location of the actualaccess resource and the sequence of the synchronization signal.Specifically, assuming that a size of a value space of the cellidentifier carried by the sequence is still 504, the value space of thecell identifier may be further expanded according to a resource locationof a first access resource in the carrier. Assuming that the carrier hasfive candidate access resources, the space can be expanded to 504*5,that is, location information of each candidate access resource mayprovide a degree of freedom of expansion. For example, in the fivecandidate access resources shown in FIG. 2, the candidate accessresource 1 may correspond to cell identifiers 0 to 503, the candidateaccess resource 2 may correspond to cell identifiers 504 to 1007, and byanalog, the candidate access resource 5 may correspond to cellidentifiers 504*4 to 504*5−1.

In addition, the UE may further acquire different random accessconfigurations of the access cell according to different actual accessresources. For a specific method, reference may be made to the method ofacquiring, by UE, different random access configurations of an accesscell according to different actual access resources in Embodiment 1 ofthe present application, and details are not described herein again inthis embodiment of the present application.

In addition, the UE may further determine a second reference signal thatis at the resource location of the actual access resource. For aspecific method, reference may be made to the method of determining, byUE, a second reference signal that is at a resource location of anactual access resource in Embodiment 1 of the present application, anddetails are not described herein again in this embodiment of the presentapplication.

In addition, after determining the resource location of the actualaccess resource of the detected actual sequence in the access cell, theUE further needs to determine an available resource in the actual accessresource. If the resource location of the actual access resource is nota frequency domain center location of the access cell, the UE mayprocess a subcarrier in a center of the actual access resource as avirtual direct current subcarrier when determining division of resourceblocks in the actual access resource. For a specific implementation,reference may be made to the method of determining, by UE, an availableresource in an actual access resource in Embodiment 1 of the presentapplication, and details are not described herein again in thisembodiment of the present application.

In this embodiment of the present application, an actual access resourceis determined by using a broadcast channel, which can ensure that asynchronization signal is consistent with that in a previous system,complexity of additional synchronization signal designs is notintroduced, a check function is implemented in receiving the broadcastchannel, and reliability is better.

Embodiment 4 of the present application: UE determines a resourcelocation of an actual access resource in an access cell according to alocation relationship, carried in resource indication information in abroadcast channel, between the actual access resource and the accesscell.

First, before detecting a synchronization signal, the UE may firstdetermine at least one candidate sequence of the synchronization signalof the UE and multiple candidate access resources of the access cell. Inthis embodiment of the present application, whether a correspondinglocation relationship exists between a candidate access resource and aresource on which the access cell is located is not limited herein inthis embodiment of the present application.

An access cell having a 20-MHz carrier bandwidth and including 100resource blocks is used as an example. Assuming that there are fivecandidate access resources in the access cell and each candidate accessresource occupies six resource blocks, location relationships of thefive candidate access resources in the 20-MHz carrier may be preset, ormay be determined by a base station randomly or according to a rule.

Then, the UE detects the synchronization signal according to the atleast one candidate sequence.

The UE detects a synchronization signal according to a candidatesequence. When the UE detects a synchronization signal and an actualsequence of the synchronization signal is one of the at least onecandidate sequence, it may be considered that the UE detects thesynchronization signal of the access cell, and the detected candidatesequence is an actual sequence of the synchronization signal of theaccess cell. Moreover, multiple actual sequences may be sent in oneaccess cell, and the multiple actual sequences are respectively sent onthe multiple candidate access resources. In this way, the UE may detectthe multiple actual sequences.

Next, the UE receives a broadcast channel of the access cell on abroadcast channel resource corresponding to an actual access resource onwhich the detected synchronization signal is located.

After the UE detects the synchronization signal, an access resource onwhich the synchronization signal is located is the actual accessresource.

The UE receives a broadcast channel of the access cell on a broadcastchannel resource corresponding to the actual access resource. Thebroadcast channel carries resource indication information, and theresource indication information is used for indicating a locationrelationship of the actual access resource in the multiple candidateaccess resources of the access cell.

The broadcast channel resource corresponding to the actual accessresource may be understood as that a resource occupied by the broadcastchannel is a subset of the actual access resource, or that a relativelyfixed location relationship exists between a resource on which thebroadcast channel is located and the actual access resource, or thelike, and these correspondences are not limited.

The UE receives the broadcast channel, where the broadcast channel maybe a physical broadcast channel or a physical broadcast channel enhancedin the future, which is not limited.

The UE may acquire the resource indication information carried in thebroadcast channel, where the resource indication information may becarried by a bit, a scrambling code, a time/frequency resource location,or the like in the broadcast channel, which is not limited herein.

The location relationship, indicated by the resource indicationinformation, of the actual access resource in the multiple candidateaccess resources of the access cell may be a location relationshipbetween the actual access resource and a center frequency point of theresource on which the cell is located, or a location relationshipbetween the actual access resource and a high frequency location in theresource on which the cell is located, or a location relationshipbetween the actual access resource and a low frequency location in theresource on which the cell is located. Generally, the locationrelationship refers to the location relationship between the actualaccess resource and the center frequency point of the resource on whichthe cell is located.

For example, the resource indication information being 1 MHz mayindicate that the actual access resource is on a resource 1 MHz higherthan the center frequency point of the access cell; and the resourceindication information being −1 MHz may indicate that the actual accessresource is on a resource 1 MHz lower than the center frequency point ofthe access cell. Certainly, “001” may also be used to indicate that theactual access resource is on the resource 1 MHz higher than the centerfrequency point of the access cell, and “002” may also be to indicatethat the actual access resource is on the resource 1 MHz lower than thecenter frequency point of the access cell.

Finally, the UE determines the resource location of the actual accessresource in the access cell according to the location relationship,indicated by the resource indication information, between the actualaccess resource and the resource on which the cell is located.

In addition, the resource indication information may further includebandwidth information of the access cell, and the UE may furtherdetermine a bandwidth of the access cell according to the bandwidthinformation of the access cell in the resource indication information.

In addition, the UE may further determine a cell identifier of theaccess cell according to the resource location of the actual accessresource in the access cell and the sequence of the synchronizationsignal. For a specific implementation, reference may be made to themethod of determining, by the UE, a cell identifier of the access cellaccording to the resource location of the actual access resource in theaccess cell and the sequence of the synchronization signal in Embodiment3 of the present application, and details are not described herein againin this embodiment of the present application.

In addition, the UE may further acquire different random accessconfigurations of the access cell according to different actual accessresources. For a specific implementation, reference may be made to themethod of acquiring, by UE, different random access configurations of anaccess cell according to different actual access resources in Embodiment1 of the present application, and details are not described herein againin this embodiment of the present application.

In addition, the UE may further determine a second reference signal thatis at the resource location of the actual access resource. For aspecific method, reference may be made to the method of determining, byUE, a second reference signal that is at a resource location of anactual access resource in Embodiment 1 of the present application, anddetails are not described herein again in this embodiment of the presentapplication.

In addition, after determining the resource location of the actualaccess resource of the detected actual sequence in the access cell, theUE further needs to determine an available resource in the actual accessresource. If the resource location of the actual access resource is nota frequency domain center location of the access cell, the UE mayprocess a subcarrier in a center of the actual access resource as avirtual direct current subcarrier when determining division of resourceblocks in the actual access resource. For a specific implementation,reference may be made to the method of determining, by UE, an availableresource in an actual access resource in Embodiment 1 of the presentapplication, and details are not described herein again in thisembodiment of the present application.

In this embodiment of the present application, an actual access resourceis determined by using a broadcast channel, which can ensure that asynchronization signal is consistent with that in a previous system,complexity of additional synchronization signal designs is notintroduced, a check function is implemented in receiving the broadcastchannel, and reliability is better.

FIG. 9 is a flowchart of another cell access resource indication methodaccording to an embodiment of the present application. The method inFIG. 9 is executed by a base station.

901: Determine an actual access resource of a current cell and an actualsequence of a synchronization signal of the current cell.

The actual access resource is at least one candidate access resource inmultiple candidate access resources of the current cell, and the actualsequence is one of at least one candidate sequence of thesynchronization signal.

902: Send the synchronization signal of the current cell on the actualaccess resource by using the actual sequence.

903: Send a broadcast channel on a broadcast channel resourcecorresponding to the actual access resource, where the broadcast channelcarries resource indication information.

The resource indication information is used for indicating the actualaccess resource in the multiple candidate access resources, or theresource indication information is used for indicating a locationrelationship between the actual access resource and a resource on whichthe current cell is located, so that UE in the current cell candetermine a resource location of the actual access resource in thecurrent cell according to the actual access resource and the resourceindication information.

In this embodiment of the present application, a resource indicationinformation is sent on a broadcast channel of an actual access resourcefor sending a synchronization signal, so that a UE side can determine aresource location of the actual access resource in a current cellaccording to the resource indication information, which can, to someextent, avoid interference impact caused by intensive cells to access bythe UE when the UE accesses the current cell, coordinate inter-cellinterference of a common control channel, and improve performance ofdetection on the common control channel.

Optionally, the resource location of the actual access resource in thecurrent cell and the actual sequence of the synchronization signal arefurther used for indicating a cell identifier of the current cell.

Optionally, after step 903, the method further includes: if the actualaccess resource includes a first actual access resource and a secondactual access resource, respectively sending a first random accessconfiguration and a second random access configuration on a broadcastchannel resource or common channel resource corresponding to the firstactual access resource and a broadcast channel resource or commonchannel resource corresponding to the second actual access resource,where the first random access configuration corresponds to the firstactual access resource, and the second random access configurationcorresponds to the second actual access resource.

Optionally, in an embodiment, after step 903, the method furtherincludes: sending a second reference signal at the resource location ofthe actual access resource. The second reference signal is a referencesignal segment clipped from a first reference signal and correspondingto the resource location, and the first reference signal is a referencesignal generated by using a center frequency point of the current cellas a center and using a quantity of resource blocks included in abandwidth of the current cell as a frequency domain width.

Optionally, in another embodiment, after step 903, the method furtherincludes: sending a second reference signal at the resource location ofthe actual access resource. The second reference signal is a referencesignal segment clipped from a frequency domain center of a firstreference signal and corresponding to a first frequency domain width,the first frequency domain width is a frequency domain width occupied bythe actual access resource, a reference signal in a bandwidth of thecurrent cell is a cyclic shift of the first reference signal, and thefirst reference signal is a reference signal generated by using a centerfrequency point of the current cell as a center and using a quantity ofresource blocks included in the bandwidth of the current cell as afrequency domain width.

Optionally, after step 903, the method further includes: if the resourcelocation of the actual access resource is not a frequency domain centerlocation of the current cell, processing a subcarrier in a center of theactual access resource as a virtual direct current subcarrier whenanalyzing division of resource blocks in the actual access resource.Further, the broadcast channel resource corresponding to the actualaccess resource is a resource on a predefined side of a center frequencypoint of the actual access resource.

The following describes the method in this embodiment of the presentapplication by using a specific embodiment.

Embodiment 5 of the present application: Resource indication informationsent by a base station on a broadcast channel resource corresponding toan actual access resource can indicate the actual access resource inmultiple candidate access resources of a current cell. The base stationsends the resource indication information on the broadcast channelresource corresponding to the actual access resource, so that on thepremise that UE can parse out a synchronization signal, the UE avoidsinterference impact caused by intensive cells to access by the UE.

First, the base station may first determine the actual access resourceand an actual sequence of the synchronization signal.

There may be multiple candidate access resources in the current cell ofthe base station. A candidate access resource is an access resource thatmay be used when the synchronization signal is sent, a candidatesequence is a sequence that may be used when the synchronization signalis sent, and each candidate sequence in the multiple candidate sequencescorresponds to one of the multiple candidate access resources.

FIG. 2 is a schematic diagram of a relationship between a cell carrierand a candidate access resource according to an embodiment of thepresent application. As shown in FIG. 2, when a cell carrier bandwidthis 20 MHz, the cell carrier bandwidth may include five candidate accessresources: candidate access resources 1 to 5 in total; when a cellcarrier bandwidth is 10 MHz, the cell carrier bandwidth may includethree candidate access resources: candidate access resources 1 to 3 intotal; when a cell carrier bandwidth is 1.4 MHz, the cell carrierbandwidth includes only a candidate access resource 1. Certainly, FIG. 2shows only a possible relationship between a candidate access resourceand a cell carrier, and there may be another possible relationship, forexample, when a cell carrier bandwidth is 10 MHz, the cell carrierbandwidth may include nine candidate access resources.

Besides a first candidate access resource, the multiple candidate accessresources of the base station may include a candidate access resource.The first candidate access resource is a resource having a frequencydomain width of N resource blocks in a center of the current cell, and Nis a preconfigured natural number, and may be specified in a protocol,or specified according to a policy of an operator. For example, in FIG.2, a candidate access resource 1 is the first candidate access resource,and occupies 1.4 MHz, that is, a frequency domain width of six resourceblocks. Besides the first candidate access resource, the multiplecandidate access resources of the base station include at least onecandidate access resource; in FIG. 2, besides the candidate accessresource 1, the multiple candidate access resources of the base stationfurther include the candidate access resource 2 to the candidate accessresource 5. Location relationships of the candidate access resources inan entire carrier resource on which the current cell is located arepreset.

In this embodiment of the present application, at least one candidateaccess resource of the current cell may be predefined, for example,defined according to a maximum carrier bandwidth, and a specific carrierbandwidth may be less than or equal to the maximum carrier bandwidth.For example, each candidate access resource may satisfy a condition thata center frequency point is on a 100-KHz grid, to facilitate cell searchby the UE, that is, detection on the synchronization signal. Forexample, in FIG. 2, a maximum bandwidth is 20 MHz and has five candidateaccess resources: the candidate access resource 1 to the candidateaccess resource 5. If an actual bandwidth is 10 MHz, there are threeactual candidate access resources.

In addition, when determining the actual access resource, the basestation further needs to determine an available resource block in theactual access resource according to a location of the actual accessresource. If the resource location of the actual access resource is nota frequency domain center location of the current cell, the base stationmay process a subcarrier in a center of the actual access resource as avirtual direct current subcarrier when determining division of resourceblocks in the actual access resource. For a specific implementation,reference may be made to a specific method of processing, by a basestation, a subcarrier in a center of an actual access resource as avirtual direct current subcarrier when determining division of resourceblocks in the actual access resource in Embodiment 2 of the presentapplication.

In addition, the candidate sequence in this embodiment of the presentapplication may be a complete sequence, or a segmental sequence in acomplete sequence.

In this embodiment of the present application, the candidate sequencemay be a Zadoff-Chu sequence or an m sequence. Certainly, a possibilityof another sequence is not excluded. Preferably, the candidate sequencein this embodiment of the present application may be a Zadoff-Chusequence. An original sequence length of the candidate sequence may beless than a sequence length of a primary synchronization sequence in anLTE release 8. The sequence length of the primary synchronizationsequence in the LTE release 8 is 63, and then a numerical value at alocation of a subcarrier at a direct current location in a carriercenter is punctured to use a final sequence whose sequence length is 62.

In an implementation manner of this embodiment of the presentapplication, on the carrier of the present application, the primarysynchronization sequence may be a sequence whose length is 61, which candistinguish an earlier-release LTE carrier and a subsequently evolvedLTE carrier.

In another implementation manner of this embodiment of the presentapplication, the original sequence length of the candidate sequence isequal to the sequence length of the primary synchronization sequence inthe LTE release 8, but an actual length of the candidate sequence isdetermined after puncture of a primary synchronization signal, forexample, two or three subcarriers are punctured.

In this case, a structure of primary synchronization signal isconsistent with that in an LTE system in the release 8. To distinguish acarrier type, a candidate sequence space may be expanded, that is, aquantity of sequences is newly designed to distinguish the carrier type,or the carrier type may be distinguished in another manner, for example,through indication by using a broadcast channel. A function of carriertype distinguishing in the foregoing is that a new carrier can usemultiple candidate access resources, while an original carrier type,that is, an earlier-release LTE system carrier, has only a resource in acarrier center.

In addition, the base station may further determine the actual accessresource in the multiple candidate access resources and the sequence ofthe synchronization signal according to a cell identifier of the currentcell. Specifically, assuming that a size of a value space of the cellidentifier carried by the sequence is still 504, the value space of thecell identifier may be further expanded according to a resource locationof a first access resource in the carrier. Assuming that the carrier hasfive candidate access resources, the space can be expanded to 504*5,that is, information about a location of each candidate access resourcein the multiple candidate access resources may provide a degree offreedom of expansion. For example, in the five candidate accessresources shown in FIG. 2, the candidate access resource 1 maycorrespond to cell identifiers 0 to 503, the candidate access resource 2may correspond to cell identifiers 504 to 1007, and by analog, thecandidate access resource 5 may correspond to cell identifiers 504*4 to504*5−1.

Then, the base station may send the synchronization signal of thecurrent cell on the actual access resource by using the actual sequence.

In this embodiment of the present application, after determining theactual access resource and the actual sequence, the base station maysend a synchronization sequence on the actual access resource.

Finally, the base station may send a broadcast channel on a broadcastchannel resource corresponding to the actual access resource. Thebroadcast channel carries resource indication information, and theresource indication information is used for indicating the actual accessresource in the multiple candidate access resources. Specifically, theresource indication information may be identification information of acandidate access resource, or a sequence number of a candidate accessresource, or the like. For example, the resource indication informationmay indicate a candidate access resource 2 by using “010”, or indicate acandidate access resource 2 by using a sequence number “2”.

In this way, after detecting the actual sequence of the current cell, aUE side may obtain the actual access resource, and then may determine alocation of the actual access resource in the current cell according tothe resource indication information received on the actual accessresource.

In addition, after sending the synchronization signal on the actualaccess resource by using the actual sequence, the base station mayfurther send different random configuration information according todifferent actual access resources. For a specific implementation,reference may be made to the method of sending, by a base station,different random configuration information according to different actualaccess resources in Embodiment 2 of the present application, and detailsare not described herein again in this embodiment of the presentapplication.

In addition, after sending the synchronization signal on the actualaccess resource by using the actual sequence, the base station mayfurther send a second reference signal at the resource location of theactual access resource. For a specific implementation, reference may bemade to the method of sending, by a base station, a second referencesignal at a resource location of an actual access resource in Embodiment2 of the present application, and details are not described herein againin this embodiment of the present application.

Embodiment 6 of the present application: Resource indication informationsent by a base station on a broadcast channel resource corresponding toan actual access resource can indicate a resource location relationshipbetween the actual access resource and a current cell. The base stationsends the resource indication information on the broadcast channelresource corresponding to the actual access resource, so that on thepremise that UE can parse out a synchronization signal, the UE avoidsinterference impact caused by intensive cells to access by the UE.

First, the base station may first determine the actual access resourceand an actual sequence of the synchronization signal.

There may be multiple candidate access resources in the current cell ofthe base station. A candidate access resource is an access resource thatmay be used when the synchronization signal is sent, a candidatesequence is a sequence that may be used when the synchronization signalis sent, and each candidate sequence in the multiple candidate sequencescorresponds to one of the multiple candidate access resources.

FIG. 2 is a schematic diagram of a relationship between a cell carrierand a candidate access resource according to an embodiment of thepresent application. As shown in FIG. 2, when a cell carrier bandwidthis 20 MHz, the cell carrier bandwidth may include five candidate accessresources: candidate access resources 1 to 5 in total; when a cellcarrier bandwidth is 10 MHz, the cell carrier bandwidth may includethree candidate access resources: candidate access resources 1 to 3 intotal; when a cell carrier bandwidth is 1.4 MHz, the cell carrierbandwidth includes only a candidate access resource 1. Certainly, FIG. 2shows only a possible relationship between a candidate access resourceand a cell carrier, and there may be another possible relationship, forexample, when a cell carrier bandwidth is 10 MHz, the cell carrierbandwidth may include nine candidate access resources.

Besides a first candidate access resource, the multiple candidate accessresources of the base station may include a candidate access resource.The first candidate access resource is a resource having a frequencydomain width of N resource blocks in a center of the current cell, and Nis a preconfigured natural number, and may be specified in a protocol,or specified according to a policy of an operator. For example, in FIG.2, a candidate access resource 1 is the first candidate access resource,and occupies 1.4 MHz, that is, a frequency domain width of six resourceblocks. Besides the first candidate access resource, the multiplecandidate access resources of the base station include at least onecandidate access resource; in FIG. 2, besides the candidate accessresource 1, the multiple candidate access resources of the base stationfurther include the candidate access resource 2 to the candidate accessresource 5. Location relationships of the candidate access resources inan entire carrier resource on which the current cell is located arepreset.

In this embodiment of the present application, at least one candidateaccess resource of the current cell may be predefined, for example,defined according to a maximum carrier bandwidth, and a specific carrierbandwidth may be less than or equal to the maximum carrier bandwidth.For example, each candidate access resource may satisfy a condition thata center frequency point is on a 100-KHz grid, to facilitate cell searchby the UE, that is, detection on the synchronization signal. Forexample, in FIG. 2, a maximum bandwidth is 20 MHz and has five candidateaccess resources: the candidate access resource 1 to the candidateaccess resource 5. If an actual bandwidth is 10 MHz, there are threeactual candidate access resources.

In addition, when determining the actual access resource, the basestation further needs to determine an available resource block in theactual access resource according to a location of the actual accessresource. If the resource location of the actual access resource is nota frequency domain center location of the current cell, the base stationmay process a subcarrier in a center of the actual access resource as avirtual direct current subcarrier when determining division of resourceblocks in the actual access resource. For a specific implementation,reference may be made to a specific method of processing, by a basestation, a subcarrier in a center of an actual access resource as avirtual direct current subcarrier when determining division of resourceblocks in the actual access resource in Embodiment 2 of the presentapplication.

In addition, the candidate sequence in this embodiment of the presentapplication may be a complete sequence, or a segmental sequence in acomplete sequence.

In this embodiment of the present application, the candidate sequencemay be a Zadoff- Chu sequence or an m sequence. Certainly, a possibilityof another sequence is not excluded. Preferably, the candidate sequencein this embodiment of the present application may be a Zadoff-Chusequence. An original sequence length of the candidate sequence may beless than a sequence length of a primary synchronization sequence in anLTE release 8. The sequence length of the primary synchronizationsequence in the LTE release 8 is 63, and then a numerical value at alocation of a subcarrier at a direct current location in a carriercenter is punctured to use a final sequence whose sequence length is 62.

In an implementation manner of this embodiment of the presentapplication, on the carrier of the present application, the primarysynchronization sequence may be a sequence whose length is 61, which candistinguish an earlier-release LTE carrier and a subsequently evolvedLTE carrier.

In another implementation manner of this embodiment of the presentapplication, the original sequence length of the candidate sequence isequal to the sequence length of the primary synchronization sequence inthe LTE release 8, but an actual length of the candidate sequence isdetermined after puncture of a primary synchronization signal, forexample, two or three subcarriers are punctured.

In this case, a structure of primary synchronization signal isconsistent with that in an LTE system in the release 8. To distinguish acarrier type, a candidate sequence space may be expanded, that is, aquantity of sequences is newly designed to distinguish the carrier type,or the carrier type may be distinguished in another manner, for example,through indication by using a broadcast channel. A function of carriertype distinguishing in the foregoing is that a new carrier can usemultiple candidate access resources, while an original carrier type,that is, an earlier-release LTE system carrier, has only a resource in acarrier center.

In addition, the base station may further determine the locationrelationship between the actual access resource and the current cell andthe sequence of the synchronization signal of the current cell accordingto a cell identifier of the current cell. Specifically, assuming that asize of a value space of the cell identifier carried by the sequence isstill 504, the value space of the cell identifier may be furtherexpanded according to a resource location of a first access resource inthe carrier. Assuming that the carrier has five candidate accessresources, respectively corresponding to five location relationships ofthe current cell, the space can be expanded to 504*5, that is,information about a location of each candidate access resource in themultiple candidate access resources may provide a degree of freedom ofexpansion. For example, in the five candidate access resources shown inFIG. 2, a location relationship between the candidate access resource 1and the current cell may correspond to cell identifiers 0 to 503, alocation relationship between the candidate access resource 2 and thecurrent cell may correspond to cell identifiers 504 to 1007, and so on,and a location relationship between the candidate access resource 5 andthe current cell may correspond to cell identifiers 504*4 to 504*5−1.

Then, the base station may send the synchronization signal of thecurrent cell on the actual access resource by using the actual sequence.

In this embodiment of the present application, after determining theactual access resource and the actual sequence, the base station maysend a synchronization sequence on the actual access resource.

Finally, the base station may send a broadcast channel on a broadcastchannel resource corresponding to the actual access resource. Thebroadcast channel carries resource indication information, and theresource indication information is used for indicating the locationrelationship between the actual access resource and the current cell.Specifically, the resource indication information may be a specificlocation relationship, or an identifier corresponding to a locationrelationship, or the like. For example, the resource indicationinformation may be “001” and indicates a resource location 10 MHz higherthan a center frequency point of the current cell, or be “10” andindicates a resource location 10 MHz higher than a center frequencypoint of the current cell.

In this way, after detecting the actual sequence of the current cell, aUE side may obtain the actual access resource, and then may determine alocation of the actual access resource in the current cell according tothe resource indication information received on the actual accessresource.

In addition, after sending the synchronization signal on the actualaccess resource by using the actual sequence, the base station mayfurther send different random configuration information according todifferent actual access resources. For a specific implementation,reference may be made to the method of sending, by a base station,different random configuration information according to different actualaccess resources in Embodiment 2 of the present application, and detailsare not described herein again in this embodiment of the presentapplication.

In addition, after sending the synchronization signal on the actualaccess resource by using the actual sequence, the base station mayfurther send a second reference signal at the resource location of theactual access resource. For a specific implementation, reference may bemade to the method of sending, by a base station, a second referencesignal at a resource location of an actual access resource in Embodiment2 of the present application, and details are not described herein againin this embodiment of the present application.

FIG. 10 is a schematic block diagram of user equipment 1000 according toan embodiment of the present application. The user equipment 1000 mayinclude a determining unit 1001 and a detecting unit 1002, where

the determining unit 1001 may be configured to determine at least onecandidate sequence of a synchronization signal of an access cell of theuser equipment and multiple candidate access resources of the accesscell, where

a corresponding location relationship exists between each candidateaccess resource in the multiple candidate access resources and aresource on which the access cell is located, and any candidate sequencein the at least one candidate sequence corresponds to one of themultiple candidate access resources; and

the detecting unit 1002 may be configured to detect the synchronizationsignal according to the at least one candidate sequence, where

the determining unit 1001 may be further configured to determine aresource location of an actual access resource corresponding to adetected actual sequence in the access cell according to the locationrelationship between each candidate access resource in the multiplecandidate access resources and the resource on which the access cell islocated and a correspondence between the any candidate sequence in theat least one candidate sequence and the multiple candidate accessresources, where

the actual sequence is one of the at least one candidate sequence, andthe actual access resource is one of the multiple candidate accessresources.

In this embodiment of the present application, the user equipment 1000determines a resource location of an actual access resource in aresource on which an access cell is located by using a locationrelationship between a candidate access resource and the resource onwhich the access cell is located and a detected actual sequence of asynchronization signal, which can, to some extent, avoid interferenceimpact caused by intensive cells to access by the UE, coordinateinter-cell interference of a common control channel, and improveperformance of detection on the common control channel.

In addition, the actual access resource is determined by detecting thesequence of the synchronization signal. Because detection on thesynchronization signal is the first step for the UE to discover acarrier, the UE can determine an access resource earliest, and detectanother signal, such as a reference signal for measurement, on theresource, rather than determine the access resource by further readinganother message such as a broadcast channel, which simplifies steps ofsystem discovery and access, makes it unnecessary to read a broadcastmessage during measurement, and improves time efficiency and powerefficiency.

Optionally, when configured to determine the resource location of theactual access resource corresponding to the detected actual sequence inthe access cell according to the location relationship between eachcandidate access resource in the multiple candidate access resources andthe resource on which the access cell is located and a correspondencebetween the any candidate sequence in the at least one candidatesequence and the multiple candidate access resources, the determiningunit is specifically configured to: determine the actual access resourcecorresponding to the actual sequence from the multiple candidate accessresources; and determine the resource location of the actual accessresource in the access cell according to the location relationshipbetween the multiple candidate access resources and the resource onwhich the access cell is located.

Optionally, the candidate sequence may be a complete sequence; or thecandidate sequence may be a segmental sequence in a complete sequence.

Optionally, besides a first candidate access resource, at least onecandidate access resource exists in the multiple candidate accessresources. The first candidate access resource is a resource having afrequency domain width of N resource blocks in a center of the accesscell, and N is a preconfigured natural number, for example, N is equalto 6. In addition, N may be specified in a protocol, or specifiedaccording to a policy of an operator.

Optionally, the determining unit 1001 is further configured to determinea location of a center frequency point of the access cell according tothe resource location of the actual access resource in the access cell.

The user equipment 1000 may further include a receiving unit 1003.

Optionally, the receiving unit 1003 may be configured to receive abroadcast channel of the access cell, and the determining unit 1001 isfurther configured to determine a bandwidth of the access cell accordingto bandwidth indication information. The broadcast channel carries thebandwidth indication information of the access cell.

Optionally, the receiving unit 1003 may be configured to: if the actualaccess resource includes a first actual access resource and a secondactual access resource, acquire a first random access configuration anda second random access configuration on the first actual access resourceand the second actual access resource, respectively, where the firstrandom access configuration corresponds to the first actual accessresource, and the second random access configuration corresponds to thesecond actual access resource.

Optionally, the determining unit 1001 is further configured to determinea second reference signal that is at the resource location of the actualaccess resource. The second reference signal is a reference signalsegment clipped from a first reference signal and corresponding to theresource location, and the first reference signal is a reference signalgenerated by using the center frequency point of the access cell as acenter and using a quantity of resource blocks included in the bandwidthof the access cell as a frequency domain width; or the second referencesignal is a reference signal segment clipped from a frequency domaincenter of a first reference signal and corresponding to a firstfrequency domain width, the first frequency domain width is a frequencydomain width occupied by the actual access resource, a reference signalin the bandwidth of the access cell is a cyclic shift of the firstreference signal, and the first reference signal is a reference signalgenerated by using the center frequency point of the access cell as acenter and using a quantity of resource blocks included in the bandwidthof the access cell as a frequency domain width.

Optionally, the determining unit 1001 is further configured to: if theresource location of the actual access resource is not a frequencydomain center location of the access cell, process a subcarrier in acenter of the actual access resource as a virtual direct currentsubcarrier when determining division of resource blocks in the actualaccess resource.

FIG. 11 is a schematic block diagram of a base station 1100 according toan embodiment of the present application. The base station 1100 mayinclude a determining unit 1101 and a sending unit 1102, where

the determining unit 1101 is configured to determine an actual accessresource of a current cell of the base station and an actual sequence ofa synchronization signal of the current cell, where the actual accessresource is at least one candidate access resource in multiple candidateaccess resources used by the current cell to send the synchronizationsignal, the actual sequence is one of at least one candidate sequence ofthe synchronization signal, and any candidate sequence in the at leastone candidate sequence corresponds to one of the multiple candidateaccess resources; and

the sending unit 1102 is configured to send the synchronization signalon the actual access resource by using the actual sequence.

In this embodiment of the present application, the base station 1100sends a synchronization signal on an actual access resource according toa correspondence between a sequence for sending the synchronizationsignal and a candidate access resource of the synchronization signal byusing an actual sequence, so that UE can determine a resource locationof the actual access resource in a current cell according to the actualsequence, the actual access resource, and a relative locationrelationship between a candidate access resource indicated by the actualsequence and the current cell, which can, to some extent, avoidinterference impact caused by intensive cells to access by the UE whenthe UE accesses the current cell, coordinate inter-cell interference ofa common control channel, and improve performance of detection on thecommon control channel.

Optionally, the one of the at least one candidate sequence is a completesequence; or the one of the at least one candidate sequence is asegmental sequence in a complete sequence.

Optionally, besides a first candidate access resource, at least onecandidate access resource exists in the multiple candidate accessresources. The first candidate access resource is a resource having afrequency domain width of N resource blocks in a center of the currentcell, and N is a preconfigured natural number. In addition, N may bespecified in a protocol, or specified according to a policy of anoperator.

Optionally, the sending unit 1102 is further configured to send abroadcast channel in the current cell. The broadcast channel carriesbandwidth indication information of the current cell, and the bandwidthindication information of the current cell is used for indicating abandwidth of the current cell.

Optionally, the sending unit 1102 is further configured to: if theactual access resource includes a first actual access resource and asecond actual access resource, send a first random access configurationof the current cell on a broadcast channel resource or common channelresource corresponding to the first actual access resource, and send asecond random access configuration of the current cell on a broadcastchannel resource or common channel resource corresponding to the secondactual access resource.

The sending unit 1102 is further configured to send a second referencesignal at the resource location of the actual access resource. Thesecond reference signal is a reference signal segment clipped from afirst reference signal and corresponding to the resource location, andthe first reference signal is a reference signal generated by using acenter frequency point of the current cell as a center and using aquantity of resource blocks included in the bandwidth of the currentcell as a frequency domain width; or the second reference signal is areference signal segment clipped from a frequency domain center of afirst reference signal and corresponding to a first frequency domainwidth, the first frequency domain width is a frequency domain widthoccupied by the actual access resource, a reference signal in thebandwidth of the current cell is a cyclic shift of the first referencesignal, and the first reference signal is a reference signal generatedby using a center frequency point of the current cell as a center andusing a quantity of resource blocks included in the bandwidth of thecurrent cell as a frequency domain width.

Optionally, when configured to determine the actual access resource ofthe current cell, the determining unit 1101 is specifically configuredto: if the resource location of the actual access resource is not afrequency domain center location of the current cell, process asubcarrier in a center of the actual access resource as a virtual directcurrent subcarrier when determining division of resource blocks in theactual access resource.

FIG. 12 is a schematic block diagram of user equipment 1200 according toan embodiment of the present application. The user equipment 1200 mayinclude a determining unit 1201, a detecting unit 1202, and a receivingunit 1203, where

the determining unit 1201 is configured to determine at least onecandidate sequence of a synchronization signal of an access cell andmultiple candidate access resources of the access cell;

the detecting unit 1202 is configured to detect the synchronizationsignal according to the at least one candidate sequence;

the receiving unit 1203 is configured to receive a broadcast channel ofthe access cell on a broadcast channel resource corresponding to anactual access resource on which the detected synchronization signal islocated, where the actual access resource is one of the multiplecandidate access resources, the broadcast channel carries resourceindication information, and the resource indication information is usedfor indicating the actual access resource in the multiple candidateaccess resources, or the resource indication information is used forindicating a location relationship between the actual access resourceand a resource on which the access cell is located; and

the determining unit 1201 is further configured to determine a resourcelocation of the actual access resource in the access cell according tothe resource indication information.

In this embodiment of the present application, the user equipment 1200determines a resource location of an actual access resource in an accesscell by using the actual access resource of a detected synchronizationsignal and resource indication information received on a broadcastchannel, which can, to some extent, avoid interference impact caused byintensive cells to access by the UE, coordinate inter-cell interferenceof a common control channel, and improve performance of detection on thecommon control channel.

Optionally, in an embodiment, when the resource indication informationis used for indicating the actual access resource in the multiplecandidate access resources, a corresponding location relationship existsbetween each candidate access resource in the multiple candidate accessresources and the resource on which the access cell is located, and thedetermining unit 1201 is specifically configured to: determine theactual access resource in the multiple candidate access resourcesaccording to the resource indication information; and determine theresource location of the actual access resource in the access cellaccording to the corresponding location relationship existing betweeneach candidate access resource in the multiple candidate accessresources and the resource on which the access cell is located.

Optionally, in another embodiment, when the resource indicationinformation is used for indicating the location relationship between theactual access resource and the resource on which the access cell islocated, when configured to determine the resource location of theactual access resource in the access cell according to the resourceindication information, the determining unit 1201 is specificallyconfigured to: determine the resource location of the actual accessresource in the access cell according to the location relationship,indicated by the resource indication information, between the actualaccess resource and the resource on which the access cell is located.

Optionally, the determining unit 1201 is further configured to determinea cell identifier of the access cell according to the resource locationof the actual access resource in the access cell and an actual sequenceof the detected synchronization signal.

Optionally, the receiving unit 1203 is further configured to: if theactual access resource includes a first actual access resource and asecond actual access resource, respectively acquire a first randomaccess configuration and a second random access configuration on thefirst actual access resource and the second actual access resource. Thefirst random access configuration corresponds to the first actual accessresource, and the second random access configuration corresponds to thesecond actual access resource.

Optionally, the determining unit 1201 is further configured to determinea second reference signal that is at the resource location of the actualaccess resource. The second reference signal is a reference signalsegment clipped from a first reference signal and corresponding to theresource location, and the first reference signal is a reference signalgenerated by using a center frequency point of the access cell as acenter and using a quantity of resource blocks included in a bandwidthof the access cell as a frequency domain width; or the second referencesignal is a reference signal segment clipped from a frequency domaincenter of a first reference signal and corresponding to a firstfrequency domain width, the first frequency domain width is a frequencydomain width occupied by the actual access resource, a reference signalin a bandwidth of the access cell is a cyclic shift of the firstreference signal, and the first reference signal is a reference signalgenerated by using a center frequency point of the access cell as acenter and using a quantity of resource blocks included in the bandwidthof the access cell as a frequency domain width.

Optionally, the determining unit 1201 is further configured to: if theresource location of the actual access resource is not a frequencydomain center location of the access cell, process a subcarrier in acenter of the actual access resource as a virtual direct currentsubcarrier when determining division of resource blocks in the actualaccess resource.

Optionally, the broadcast channel resource corresponding to the actualaccess resource is a resource on a predefined side of a center frequencypoint of the actual access resource.

FIG. 13 is a schematic block diagram of a base station 1300 according toan embodiment of the present application. The base station 1300 mayinclude a determining unit 1301 and a sending unit 1302, where

the determining unit 1301 is configured to determine an actual accessresource of a current cell of the base station and an actual sequence ofa synchronization signal of the current cell, where the actual accessresource is at least one candidate access resource in multiple candidateaccess resources of the current cell, and the actual sequence is one ofat least one candidate sequence of the synchronization signal;

the sending unit 1302 is configured to send the synchronization signalof the current cell on the actual access resource by using the actualsequence; and

the sending unit 1302 is further configured to send a broadcast channelon a broadcast channel resource corresponding to the actual accessresource, where the broadcast channel carries resource indicationinformation, and the resource indication information is used forindicating the actual access resource in the multiple candidate accessresources, or the resource indication information is used for indicatinga location relationship between the actual access resource and aresource on which the current cell is located.

In this embodiment of the present application, the base station 1300sends a resource indication information on a broadcast channel of anactual access resource for sending a synchronization signal, so that aUE side can determine a resource location of the actual access resourcein a current cell according to the resource indication information,which can, to some extent, avoid interference impact caused by intensivecells to access by UE when the UE accesses the current cell, coordinateinter-cell interference of a common control channel, and improveperformance of detection on the common control channel.

Optionally, the resource location of the actual access resource in thecurrent cell and the actual sequence of the synchronization signal arefurther used for indicating a cell identifier of the current cell.

Optionally, the sending unit 1302 is further configured to: if theactual access resource includes a first actual access resource and asecond actual access resource, respectively send a first random accessconfiguration and a second random access configuration on a broadcastchannel resource or common channel resource corresponding to the firstactual access resource and a broadcast channel resource or commonchannel resource corresponding to the second actual access resource,where the first random access configuration corresponds to the firstactual access resource, and the second random access configurationcorresponds to the second actual access resource.

Optionally, the sending unit 1302 is further configured to send a secondreference signal at the resource location of the actual access resource.The second reference signal is a reference signal segment clipped from afirst reference signal and corresponding to the resource location, andthe first reference signal is a reference signal generated by using acenter frequency point of the current cell as a center and using aquantity of resource blocks included in a bandwidth of the current cellas a frequency domain width; or the second reference signal is areference signal segment clipped from a frequency domain center of afirst reference signal and corresponding to a first frequency domainwidth, the first frequency domain width is a frequency domain widthoccupied by the actual access resource, a reference signal in abandwidth of the current cell is a cyclic shift of the first referencesignal, and the first reference signal is a reference signal generatedby using a center frequency point of the current cell as a center andusing a quantity of resource blocks included in the bandwidth of thecurrent cell as a frequency domain width.

Optionally, the determining unit 1301 is specifically configured to: ifthe resource location of the actual access resource is not a frequencydomain center location of the current cell, process a subcarrier in acenter of the actual access resource as a virtual direct currentsubcarrier when determining division of resource blocks in the actualaccess resource.

Optionally, the broadcast channel resource corresponding to the actualaccess resource is a resource on a predefined side of a center frequencypoint of the actual access resource.

FIG. 14 is a simplified structural diagram of user equipment 1400according to an embodiment of the present application. The userequipment 1400 may include: a processor 1402, a memory 1403, atransmitter 1401, and a receiver 1404.

The receiver 1404, the transmitter 1401, the processor 1402, and thememory 1403 are connected to each other by using a bus 1406 system. Thebus 1406 may be a industry standard architecture (ISA) bus, a peripheralcomponent interconnect (PCI) bus, an extended industry standardarchitecture (EISA) bus, or the like. The bus may be classified into anaddress bus, a data bus, a control bus, and the like. For ease ofillustration, in FIG. 14, the bus is represented by using only onedouble-sided arrow, which, however, does not indicate that there is onlyone bus or only one type of bus. In specific application, thetransmitter 1401 and the receiver 1404 may be coupled to an antenna1405.

The memory 1403 is configured to store a program. Specifically, theprogram may include program code, where the program code includes acomputer operation instruction. The memory 1403 may include a read-onlymemory and a random access memory, and provides an instruction and datato the processor 1402. The memory 1403 may include a high-speed randomaccess memory (RAM) memory, and may further include a non-volatilememory, for example, at least one magnetic disk memory.

The processor 1402 executes the program stored in the memory 1403, todetermine at least one candidate sequence of a synchronization signal ofan access cell of the user equipment and multiple candidate accessresources of the access cell, where a corresponding locationrelationship exists between each candidate access resource in themultiple candidate access resources and a resource on which the accesscell is located, and any candidate sequence in the at least onecandidate sequence corresponds to one of the multiple candidate accessresources. The processor 1402 is further configured to detect thesynchronization signal according to the at least one candidate sequence,and determine a resource location of an actual access resourcecorresponding to a detected actual sequence in the access cell accordingto the location relationship between each candidate access resource inthe multiple candidate access resources and the resource on which theaccess cell is located and a correspondence between the any candidatesequence in the at least one candidate sequence and the multiplecandidate access resources. The actual sequence is one of the at leastone candidate sequence, and the actual access resource is one of themultiple candidate access resources.

Any one of the foregoing embodiments like that in FIG. 1 of the presentapplication and the method disclosed in Embodiment 1 of the presentapplication and executed by a coordination device may be applied to theprocessor 1402, or implemented by the processor 1402. The processor 1402may be an integrated circuit chip and has a signal processingcapability. In an implementation process, steps of the foregoing methodmay be completed by using an integrated logical circuit of hardware inthe processor 1402 or an instruction in a form of software. Theprocessor 1402 may be a general-purpose processor, including a centralprocessing unit (CPU), a network processor (NP), and the like; and mayalso be a digital signal processor (DSP), an application-specificintegrated circuit (ASIC), a field programmable gate array (FPGA) oranother programmable logical device, discrete gate or transistor logicdevice, or discrete hardware assembly. The processor may implement orexecute methods, steps, and logical block diagrams disclosed in theembodiments of the present application. The general- purpose processormay be a microprocessor or the processor may be any regular processor,or the like. Steps of the methods disclosed with reference to theembodiments of the present application may be directly executed andcompleted by means of a hardware decoding processor, or may be executedand completed by using a combination of hardware and software modules ina decoding processor. The software modules may be located in a maturestorage medium in the art, such as a random access memory, a flashmemory, a read-only memory, a programmable read-only memory, anelectronically erasable programmable memory, or a register. The storagemedium is located in the memory 1403, and the processor 1402 readsinformation in the memory 1403, and completes the steps of the methodsin combination with hardware of the processor 1402.

In this embodiment of the present application, the user equipment 1400determines a resource location of an actual access resource in aresource on which an access cell is located by using a locationrelationship between a candidate access resource and the resource onwhich the access cell is located and a detected actual sequence of asynchronization signal, which can, to some extent, avoid interferenceimpact caused by intensive cells to access by the UE, coordinateinter-cell interference of a common control channel, and improveperformance of detection on the common control channel.

In addition, the actual access resource is determined by detecting thesequence of the synchronization signal. Because detection on thesynchronization signal is the first step for the UE to discover acarrier, the UE can determine an access resource earliest, and detectanother signal, such as a reference signal for measurement, on theresource, rather than determine the access resource by further readinganother message such as a broadcast channel, which simplifies steps ofsystem discovery and access, makes it unnecessary to read a broadcastmessage during measurement, and improves time efficiency and powerefficiency.

Optionally, when configured to determine the resource location of theactual access resource corresponding to the detected actual sequence inthe access cell according to the location relationship between eachcandidate access resource in the multiple candidate access resources andthe resource on which the access cell is located and a correspondencebetween the any candidate sequence in the at least one candidatesequence and the multiple candidate access resources, the processor 1402is specifically configured to: determine the actual access resourcecorresponding to the actual sequence from the multiple candidate accessresources; and determine the resource location of the actual accessresource in the access cell according to the location relationshipbetween the multiple candidate access resources and the resource onwhich the access cell is located.

Optionally, the candidate sequence may be a complete sequence; or thecandidate sequence may be a segmental sequence in a complete sequence.

Optionally, besides a first candidate access resource, at least onecandidate access resource exists in the multiple candidate accessresources. The first candidate access resource is a resource having afrequency domain width of N resource blocks in a center of the accesscell, and N is a preconfigured natural number, for example, N is equalto 6. In addition, N may be specified in a protocol, or specifiedaccording to a policy of an operator.

Optionally, the processor 1402 is further configured to determine alocation of a center frequency point of the access cell according to theresource location of the actual access resource in the access cell.

Optionally, the receiver 1404 may be configured to receive a broadcastchannel of the access cell, and the processor 1402 is further configuredto determine a bandwidth of the access cell according to bandwidthindication information. The broadcast channel carries the bandwidthindication information of the access cell.

Optionally, the receiver 1404 may be configured to: if the actual accessresource includes a first actual access resource and a second actualaccess resource, respectively acquire a first random accessconfiguration and a second random access configuration on the firstactual access resource and the second actual access resource. The firstrandom access configuration corresponds to the first actual accessresource, and the second random access configuration corresponds to thesecond actual access resource.

Optionally, the processor 1402 is further configured to determine asecond reference signal that is at the resource location of the actualaccess resource. The second reference signal is a reference signalsegment clipped from a first reference signal and corresponding to theresource location, and the first reference signal is a reference signalgenerated by using the center frequency point of the access cell as acenter and using a quantity of resource blocks included in the bandwidthof the access cell as a frequency domain width; or the second referencesignal is a reference signal segment clipped from a frequency domaincenter of a first reference signal and corresponding to a firstfrequency domain width, the first frequency domain width is a frequencydomain width occupied by the actual access resource, a reference signalin the bandwidth of the access cell is a cyclic shift of the firstreference signal, and the first reference signal is a reference signalgenerated by using the center frequency point of the access cell as acenter and using a quantity of resource blocks included in the bandwidthof the access cell as a frequency domain width.

Optionally, the processor 1402 is further configured to: if the resourcelocation of the actual access resource is not a frequency domain centerlocation of the access cell, process a subcarrier in a center of theactual access resource as a virtual direct current subcarrier whendetermining division of resource blocks in the actual access resource.

FIG. 15 is a simplified structural diagram of a base station 1500according to an embodiment of the present application. The base station1500 may include: a processor 1502, a memory 1503, a transmitter 1501,and a receiver 1504.

The receiver 1504, the transmitter 1501, the processor 1502, and thememory 1503 are connected to each other by using a bus 1506 system. Thebus 1506 may be an ISA bus, a PCI bus, an EISA bus, or the like. The busmay be classified into an address bus, a data bus, a control bus, andthe like. For ease of illustration, in FIG. 15, the bus is representedby using only one double-sided arrow, which, however, does not indicatethat there is only one bus or only one type of bus. In specificapplication, the transmitter 1501 and the receiver 1504 may be coupledto an antenna 1505.

The memory 1503 is configured to store a program. Specifically, theprogram may include program code, where the program code includes acomputer operation instruction. The memory 1503 may include a read-onlymemory and a random access memory, and provides an instruction and datato the processor 1502. The memory 1503 may include a high-speed RAMmemory, and may further include a non-volatile memory (non-volatilememory), for example, at least one magnetic disk memory.

The processor 1502 executes the program stored in the memory 1503, todetermine an actual access resource of a current cell of the basestation 1500 and an actual sequence of a synchronization signal of thecurrent cell, and send, by using the transmitter 1501, thesynchronization signal on the actual access resource by using the actualsequence. The actual access resource is at least one candidate accessresource in multiple candidate access resources used by the current cellto send the synchronization signal, the actual sequence is one of atleast one candidate sequence of the synchronization signal, and anycandidate sequence in the at least one candidate sequence corresponds toone of the multiple candidate access resources.

Any one of the foregoing embodiments like that in FIG. 7 of the presentapplication and the method disclosed in Embodiment 2 of the presentapplication and executed by a coordination device may be applied to theprocessor 1502, or implemented by the processor 1502. The processor 1502may be an integrated circuit chip and has a signal processingcapability. In an implementation process, steps of the foregoing methodmay be completed by using an integrated logical circuit of hardware inthe processor 1502 or an instruction in a form of software. Theprocessor 1502 may be a general-purpose processor, including a centralprocessing unit (CPU), a network processor (NP), and the like; and mayalso be a digital signal processor (DSP), an application-specificintegrated circuit (ASIC), a field programmable gate array (FPGA) oranother programmable logical device, discrete gate or transistor logicdevice, or discrete hardware assembly. The processor may implement orexecute methods, steps, and logical block diagrams disclosed in theembodiments of the present application. The general- purpose processormay be a microprocessor or the processor may be any regular processor,or the like. Steps of the methods disclosed with reference to theembodiments of the present application may be directly executed andcompleted by means of a hardware decoding processor, or may be executedand completed by using a combination of hardware and software modules ina decoding processor. The software modules may be located in a maturestorage medium in the art, such as a random access memory, a flashmemory, a read-only memory, a programmable read-only memory, anelectronically erasable programmable memory, or a register. The storagemedium is located in the memory 1503, and the processor 1502 readsinformation in the memory 1503, and completes the steps of the methodsin combination with hardware of the processor 1502.

In this embodiment of the present application, the base station 1500sends a synchronization signal on an actual access resource according toa correspondence between a sequence for sending the synchronizationsignal and a candidate access resource of the synchronization signal byusing an actual sequence, so that UE can determine a resource locationof the actual access resource in a current cell according to the actualsequence, the actual access resource, and a relative locationrelationship between a candidate access resource indicated by the actualsequence and the current cell, which can, to some extent, avoidinterference impact caused by intensive cells to access by the UE whenthe UE accesses the current cell, coordinate inter-cell interference ofa common control channel, and improve performance of detection on thecommon control channel.

Optionally, the one of the at least one candidate sequence is a completesequence; or the one of the at least one candidate sequence is asegmental sequence in a complete sequence.

Optionally, besides a first candidate access resource, at least onecandidate access resource exists in the multiple candidate accessresources. The first candidate access resource is a resource having afrequency domain width of N resource blocks in a center of the currentcell, and N is a preconfigured natural number. In addition, N may bespecified in a protocol, or specified according to a policy of anoperator.

Optionally, the processor 1502 is further configured to send a broadcastchannel in the current cell by using the transmitter 1501. The broadcastchannel carries bandwidth indication information of the current cell,and the bandwidth indication information of the current cell is used forindicating a bandwidth of the current cell.

Optionally, the processor 1502 is further configured to: if the actualaccess resource includes a first actual access resource and a secondactual access resource, by using the transmitter 1501, send a firstrandom access configuration of the current cell on a broadcast channelresource or common channel resource corresponding to the first actualaccess resource, and send a second random access configuration of thecurrent cell on a broadcast channel resource or common channel resourcecorresponding to the second actual access resource.

Optionally, the processor 1502 is further configured to send a secondreference signal at the resource location of the actual access resourceby using the transmitter 1501. The second reference signal is areference signal segment clipped from a first reference signal andcorresponding to the resource location, and the first reference signalis a reference signal generated by using a center frequency point of thecurrent cell as a center and using a quantity of resource blocksincluded in the bandwidth of the current cell as a frequency domainwidth; or the second reference signal is a reference signal segmentclipped from a frequency domain center of a first reference signal andcorresponding to a first frequency domain width, the first frequencydomain width is a frequency domain width occupied by the actual accessresource, a reference signal in the bandwidth of the current cell is acyclic shift of the first reference signal, and the first referencesignal is a reference signal generated by using a center frequency pointof the current cell as a center and using a quantity of resource blocksincluded in the bandwidth of the current cell as a frequency domainwidth.

Optionally, when configured to determine the actual access resource ofthe current cell of the base station 1500, the processor 1502 isspecifically configured to: if the resource location of the actualaccess resource is not a frequency domain center location of the currentcell, process a subcarrier in a center of the actual access resource asa virtual direct current subcarrier when determining division ofresource blocks in the actual access resource.

FIG. 16 is a simplified structural diagram of user equipment 1600according to an embodiment of the present application. The userequipment 1600 may include: a processor 1602, a memory 1603, atransmitter 1601, and a receiver 1604.

The receiver 1604, the transmitter 1601, the processor 1602, and thememory 1603 are connected to each other by using a bus 1606 system. Thebus 1606 may be an ISA bus, a PCI bus, an EISA bus, or the like. The busmay be classified into an address bus, a data bus, a control bus, andthe like. For ease of illustration, in FIG. 16, the bus is representedby using only one double-sided arrow, which, however, does not indicatethat there is only one bus or only one type of bus. In specificapplication, the transmitter 1601 and the receiver 1604 may be coupledto an antenna 1605.

The memory 1603 is configured to store a program. Specifically, theprogram may include program code, where the program code includes acomputer operation instruction. The memory 1603 may include a read-onlymemory and a random access memory, and provides an instruction and datato the processor 1602. The memory 1603 may include a high-speed RAMmemory, and may further include a non-volatile memory, for example, atleast one magnetic disk memory.

The processor 1602 executes the program stored in the memory 1603, todetermine at least one candidate sequence of a synchronization signal ofan access cell and multiple candidate access resources of the accesscell, detect the synchronization signal according to the at least onecandidate sequence by using the receiver 1604, and receive, by using thereceiver 1604, a broadcast channel of the access cell on a broadcastchannel resource corresponding to an actual access resource on which thedetected synchronization signal is located, where the actual accessresource is one of the multiple candidate access resources, thebroadcast channel carries resource indication information, and theresource indication information is used for indicating the actual accessresource in the multiple candidate access resources, or the resourceindication information is used for indicating a location relationshipbetween the actual access resource and a resource on which the accesscell is located; and the processor 1602 is further configured todetermine a resource location of the actual access resource in theaccess cell according to the resource indication information.

Any one of the foregoing embodiments like that in FIG. 8 of the presentapplication and the methods disclosed in Embodiments 3 and 4 of thepresent application and executed by a coordination device may be appliedto the processor 1602, or implemented by the processor 1602. Theprocessor 1602 may be an integrated circuit chip and has a signalprocessing capability. In an implementation process, steps of theforegoing method may be completed by using an integrated logical circuitof hardware in the processor 1602 or an instruction in a form ofsoftware. The processor 1602 may be a general-purpose processor,including a central processing unit (CPU), a network processor (NP), andthe like; and may also be a digital signal processor (DSP), anapplication-specific integrated circuit (ASIC), a field programmablegate array (FPGA) or another programmable logical device, discrete gateor transistor logic device, or discrete hardware assembly. The processormay implement or execute methods, steps, and logical block diagramsdisclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or the processor may be anyregular processor, or the like. Steps of the methods disclosed withreference to the embodiments of the present application may be directlyexecuted and completed by means of a hardware decoding processor, or maybe executed and completed by using a combination of hardware andsoftware modules in a decoding processor. The software modules may belocated in a mature storage medium in the art, such as a random accessmemory, a flash memory, a read-only memory, a programmable read-onlymemory, an electronically erasable programmable memory, or a register.The storage medium is located in the memory 1603, and the processor 1602reads information in the memory 1603, and completes the steps of themethods in combination with hardware of the processor 1602.

In this embodiment of the present application, the user equipment 1600determines a resource location of an actual access resource in an accesscell by using the actual access resource of a detected synchronizationsignal and resource indication information received on a broadcastchannel, which can, to some extent, avoid interference impact caused byintensive cells to access by the UE, coordinate inter-cell interferenceof a common control channel, and improve performance of detection on thecommon control channel.

Optionally, in an embodiment, when the resource indication informationis used for indicating the actual access resource in the multiplecandidate access resources, a corresponding location relationship existsbetween each candidate access resource in the multiple candidate accessresources and the resource on which the access cell is located, and theprocessor 1602 is specifically configured to: determine the actualaccess resource in the multiple candidate access resources according tothe resource indication information; and determine the resource locationof the actual access resource in the access cell according to thecorresponding location relationship existing between each candidateaccess resource in the multiple candidate access resources and theresource on which the access cell is located.

Optionally, in another embodiment, when the resource indicationinformation is used for indicating the location relationship between theactual access resource and the resource on which the access cell islocated, when configured to determine the resource location of theactual access resource in the access cell according to the resourceindication information, the processor 1602 is specifically configuredto: determine the resource location of the actual access resource in theaccess cell according to the location relationship, indicated by theresource indication information, between the actual access resource andthe resource on which the access cell is located.

Optionally, the processor 1602 is further configured to determine a cellidentifier of the access cell according to the resource location of theactual access resource in the access cell and an actual sequence of thedetected synchronization signal.

Optionally, the processor 1602 is further configured to: if the actualaccess resource includes a first actual access resource and a secondactual access resource, respectively acquire a first random accessconfiguration and a second random access configuration on the firstactual access resource and the second actual access resource by usingthe receiver 1603. The first random access configuration corresponds tothe first actual access resource, and the second random accessconfiguration corresponds to the second actual access resource.

Optionally, the processor 1602 is further configured to determine asecond reference signal that is at the resource location of the actualaccess resource. The second reference signal is a reference signalsegment clipped from a first reference signal and corresponding to theresource location, and the first reference signal is a reference signalgenerated by using a center frequency point of the access cell as acenter and using a quantity of resource blocks included in a bandwidthof the access cell as a frequency domain width; or the second referencesignal is a reference signal segment clipped from a frequency domaincenter of a first reference signal and corresponding to a firstfrequency domain width, the first frequency domain width is a frequencydomain width occupied by the actual access resource, a reference signalin a bandwidth of the access cell is a cyclic shift of the firstreference signal, and the first reference signal is a reference signalgenerated by using a center frequency point of the access cell as acenter and using a quantity of resource blocks included in the bandwidthof the access cell as a frequency domain width.

Optionally, the processor 1602 is further configured to: if the resourcelocation of the actual access resource is not a frequency domain centerlocation of the access cell, process a subcarrier in a center of theactual access resource as a virtual direct current subcarrier whendetermining division of resource blocks in the actual access resource.

Optionally, the broadcast channel resource corresponding to the actualaccess resource is a resource on a predefined side of a center frequencypoint of the actual access resource.

FIG. 17 is a simplified structural diagram of a base station 1700according to an embodiment of the present application. The base station1700 may include: a processor 1702, a memory 1703, a transmitter 1701,and a receiver 1704.

The receiver 1704, the transmitter 1701, the processor 1702, and thememory 1703 are connected to each other by using a bus 1706 system. Thebus 1706 may be an ISA bus, a PCI bus, an EISA bus, or the like. The busmay be classified into an address bus, a data bus, a control bus, andthe like. For ease of illustration, in FIG. 17, the bus is representedby using only one double-sided arrow, which, however, does not indicatethat there is only one bus or only one type of bus. In specificapplication, the transmitter 1701 and the receiver 1704 may be coupledto an antenna 1705.

The memory 1703 is configured to store a program. Specifically, theprogram may include program code, where the program code includes acomputer operation instruction. The memory 1703 may include a read-onlymemory and a random access memory, and provides an instruction and datato the processor 1702. The memory 1703 may include a high-speed RAMmemory, and may further include a non-volatile memory, for example, atleast one magnetic disk memory.

The processor 1702 executes the program stored in the memory 1703, todetermine an actual access resource of a current cell of the basestation and an actual sequence of a synchronization signal of thecurrent cell. The actual access resource is at least one candidateaccess resource in multiple candidate access resources of the currentcell, and the actual sequence is one of at least one candidate sequenceof the synchronization signal. The processor 1702 is further configuredto send, by using the transmitter 1701, the synchronization signal ofthe current cell on the actual access resource by using the actualsequence, and send, by using the transmitter 1701, a broadcast channelon a broadcast channel resource corresponding to the actual accessresource. The broadcast channel carries resource indication information,and the resource indication information is used for indicating theactual access resource in the multiple candidate access resources, orthe resource indication information is used for indicating a locationrelationship between the actual access resource and a resource on whichthe current cell is located.

Any one of the foregoing embodiments like that in FIG. 9 of the presentapplication and the methods disclosed in Embodiments 5 and 6 of thepresent application and executed by a coordination device may be appliedto the processor 1702, or implemented by the processor 1702. Theprocessor 1702 may be an integrated circuit chip and has a signalprocessing capability. In an implementation process, steps of theforegoing method may be completed by using an integrated logical circuitof hardware in the processor 1702 or an instruction in a form ofsoftware. The processor 1702 may be a general-purpose processor,including a central processing unit (CPU), a network processor (NP), andthe like; and may also be a digital signal processor (DSP), anapplication-specific integrated circuit (ASIC), a field programmablegate array (FPGA) or another programmable logical device, discrete gateor transistor logic device, or discrete hardware assembly. The processormay implement or execute methods, steps, and logical block diagramsdisclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or the processor may be anyregular processor, or the like. Steps of the methods disclosed withreference to the embodiments of the present application may be directlyexecuted and completed by means of a hardware decoding processor, or maybe executed and completed by using a combination of hardware andsoftware modules in a decoding processor. The software modules may belocated in a mature storage medium in the art, such as a random accessmemory, a flash memory, a read-only memory, a programmable read-onlymemory, an electronically erasable programmable memory, or a register.The storage medium is located in the memory 1703, and the processor 1702reads information in the memory 1703, and completes the steps of themethods in combination with hardware of the processor 1702.

In this embodiment of the present application, the base station 1700sends a resource indication information on a broadcast channel of anactual access resource for sending a synchronization signal, so that aUE side can determine a resource location of the actual access resourcein a current cell according to the resource indication information,which can, to some extent, avoid interference impact caused by intensivecells to access by UE when the UE accesses the current cell, coordinateinter-cell interference of a common control channel, and improveperformance of detection on the common control channel.

Optionally, the resource location of the actual access resource in thecurrent cell and the actual sequence of the synchronization signal arefurther used for indicating a cell identifier of the current cell.

Optionally, the processor 1702 is further configured to: if the actualaccess resource includes a first actual access resource and a secondactual access resource, respectively send, by using the transmitter1701, a first random access configuration and a second random accessconfiguration on a broadcast channel resource or common channel resourcecorresponding to the first actual access resource and a broadcastchannel resource or common channel resource corresponding to the secondactual access resource. The first random access configurationcorresponds to the first actual access resource, and the second randomaccess configuration corresponds to the second actual access resource.

Optionally, the processor 1702 is further configured to send a secondreference signal at the resource location of the actual access resourceby using the transmitter 1701. The second reference signal is areference signal segment clipped from a first reference signal andcorresponding to the resource location, and the first reference signalis a reference signal generated by using a center frequency point of thecurrent cell as a center and using a quantity of resource blocksincluded in a bandwidth of the current cell as a frequency domain width;or the second reference signal is a reference signal segment clippedfrom a frequency domain center of a first reference signal andcorresponding to a first frequency domain width, the first frequencydomain width is a frequency domain width occupied by the actual accessresource, a reference signal in a bandwidth of the current cell is acyclic shift of the first reference signal, and the first referencesignal is a reference signal generated by using a center frequency pointof the current cell as a center and using a quantity of resource blocksincluded in the bandwidth of the current cell as a frequency domainwidth.

Optionally, when configured to determine the actual access resource ofthe current cell of the base station 1700, the processor 1702 isspecifically configured to: if the resource location of the actualaccess resource is not a frequency domain center location of the currentcell, process a subcarrier in a center of the actual access resource asa virtual direct current subcarrier when determining division ofresource blocks in the actual access resource.

Optionally, the broadcast channel resource corresponding to the actualaccess resource is a resource on a predefined side of a center frequencypoint of the actual access resource.

It should be understood that sequence numbers of the foregoing processesdo not mean execution sequences in various embodiments of the presentapplication. The execution sequences of the processes should bedetermined according to functions and internal logic of the processes,and should not be construed as any limitation on the implementationprocesses of the embodiments of the present application.

A person of ordinary skill in the art may be aware that, in combinationwith the examples described in the embodiments disclosed in thisspecification, units and algorithm steps may be implemented byelectronic hardware or a combination of computer software and electronichardware. Whether the functions are performed by hardware or softwaredepends on particular applications and design constraint conditions ofthe technical solutions. A person skilled in the art may use differentmethods to implement the described functions for each particularapplication, but it should not be considered that the implementationgoes beyond the scope of the present application.

It may be clearly understood by a person skilled in the art that, forthe purpose of convenient and brief description, for a detailed workingprocess of the foregoing system, apparatus, and unit, reference may bemade to a corresponding process in the foregoing method embodiments, anddetails are not described herein again.

In the several embodiments provided in the present application, itshould be understood that the disclosed system, apparatus, and methodmay be implemented in other manners. For example, the describedapparatus embodiment is merely exemplary. For example, the unit divisionis merely logical function division and may be other division in actualimplementation. For example, a plurality of units or components may becombined or integrated into another system, or some features may beignored or not performed. In addition, the displayed or discussed mutualcouplings or direct couplings or communication connections may beimplemented by using some interfaces. The indirect couplings orcommunication connections between the apparatuses or units may beimplemented in electronic, mechanical, or other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on a plurality ofnetwork units. Some or all of the units may be selected according toactual needs to achieve the objectives of the solutions of theembodiments.

In addition, functional units in the embodiments of the presentapplication may be integrated into one processing unit, or each of theunits may exist alone physically, or two or more units are integratedinto one unit.

When the functions are implemented in the form of a software functionalunit and sold or used as an independent product, the functions may bestored in a computer-readable storage medium. Based on such anunderstanding, the technical solutions of the present applicationessentially, or the part contributing to the prior art, or some of thetechnical solutions may be implemented in a form of a software product.The computer software product is stored in a storage medium, andincludes several instructions for instructing a computer device (whichmay be a personal computer, a server, or a network device) to performall or some of the steps of the methods described in the embodiments ofthe present application. The foregoing storage medium includes: anymedium that can store program code, such as a universal serial bus (USB)flash drive, a removable hard disk, a read-only memory (ROM), a randomaccess memory (RAM), a magnetic disk, or an optical disc.

The foregoing descriptions are merely specific implementation manners ofthe present application, but are not intended to limit the protectionscope of the present application. Any variation or replacement readilyfigured out by a person skilled in the art within the technical scopedisclosed in the present application shall fall within the protectionscope of the present application. Therefore, the protection scope of thepresent application shall be subject to the protection scope of theclaims.

What is claimed is:
 1. A method for obtaining access resourceinformation, comprising: detecting, by a terminal device, asynchronization signal of a cell; and receiving, by the terminal device,resource indication information and bandwidth information; wherein theresource indication information indicates a frequency offset between alocation of an actual access resource on which the synchronizationsignal is detected and a lowest frequency location of a resource onwhich the cell is located; and wherein the bandwidth information isbandwidth information of the cell.
 2. The method according to claim 1,wherein the resource on which the cell is located is a resource of anentire carrier on which the cell is located.
 3. The method according toclaim 1, wherein the actual access resource comprises a first actualaccess resource and a second actual access resource, the first actualaccess resource corresponds to a first random access configuration, andthe second actual access resource corresponds to a second random accessconfiguration, and the first random access configuration and the secondrandom access configuration are uplink random access configurations, andeach uplink random access configuration comprises preamble sequences foruplink random access.
 4. The method according to claim 1, wherein theresource indication information is carried by a broadcast channel of thecell, and receiving the resource indication information comprises:receiving, by the terminal device, the resource indication informationon a broadcast channel resource corresponding to the actual accessresource.
 5. The method according to claim 1, further comprising:determining, by the terminal device, a cell identifier of the cellaccording to the location of the actual access resource and a sequenceof the synchronization signal.
 6. The method according to claim 1,further comprising: determining, by the terminal device, a cellidentifier of the cell according to sequence information of thesynchronization signal.
 7. A method for indicating access resourceinformation, comprising: sending, by a network device, a synchronizationsignal; and sending, by the network device, resource indicationinformation and bandwidth information; wherein the resource indicationinformation indicates a frequency offset between a location of an actualaccess resource on which the synchronization signal is located and alowest frequency location of a resource on which a current cell of aterminal device is located; and wherein the bandwidth information isbandwidth information of the current cell;
 8. The method according toclaim 7, wherein the resource on which the current cell is located is aresource of an entire carrier on which the current cell is located. 9.The method according to claim 7, wherein the actual access resourcecomprises a first actual access resource and a second actual accessresource, the first actual access resource corresponds to a first randomaccess configuration, and the second actual access resource correspondsto a second random access configuration, and the first random accessconfiguration and the second random access configuration are uplinkrandom access configurations, and each uplink random accessconfiguration comprises preamble sequences for uplink random access. 10.The method according to claim 7, further comprising: determining, by thenetwork device, an actual sequence of the synchronization signal;wherein sending the synchronization signal comprises: sending, by thenetwork device, the synchronization signal on the actual access resourceby using the actual sequence.
 11. The method according to claim 7,wherein the resource indication information is carried by a broadcastchannel of the current cell, and sending the resource indicationinformation comprises: sending, by the network device, the resourceindication information on a broadcast channel resource corresponding tothe actual access resource.
 12. An apparatus, comprising: one or moreprocessors, and a storage medium storing program instructions; wherein,when executed by the one or more processors, the program instructionscause the apparatus to: detect a synchronization signal of a cell; andreceive resource indication information and bandwidth information;wherein the resource indication information indicates a frequency offsetbetween a location of an actual access resource on which thesynchronization signal is detected and a lowest frequency location of aresource on which the cell is located; and wherein the bandwidthinformation is bandwidth information of the cell.
 13. The apparatusaccording to claim 12, wherein the resource on which the cell is locatedis a resource of an entire carrier resource on which the cell islocated.
 14. The apparatus according to claim 12, wherein the actualaccess resource comprises a first actual access resource and a secondactual access resource, the first actual access resource corresponds toa first random access configuration, and the second actual accessresource corresponds to a second random access configuration, and thefirst random access configuration and the second random accessconfiguration are uplink random access configurations, and each uplinkrandom access configuration comprises preamble sequences for uplinkrandom access.
 15. The apparatus according to claim 12, wherein theresource indication information is carried by a broadcast channel of thecell, and in receiving resource indication information, the programinstructions cause the apparatus to: receive the resource indicationinformation on a broadcast channel resource corresponding to the actualaccess resource.
 16. The apparatus according to claim 12, wherein theprogram instructions further cause the apparatus to: determine a cellidentifier of the cell according to the location of the actual accessresource and a sequence of the synchronization signal.
 17. The apparatusaccording to claim 12, wherein the program instructions further causethe apparatus to: determine a cell identifier of the cell according tosequence information of the synchronization signal.
 18. An apparatus,comprising: one or more processors, and a storage medium storing programinstructions; wherein, when executed by the one or more processors, theprogram instructions cause the apparatus to: send a synchronizationsignal; and send resource indication information and bandwidthinformation; wherein the resource indication information indicates afrequency offset between a location of an actual access resource onwhich the synchronization signal is located and a lowest frequencylocation of a resource on which a current cell of a terminal device islocated; and wherein the bandwidth information is bandwidth informationof the current cell.
 19. The apparatus according to claim 18, whereinthe resource on which the current cell is located is a resource of anentire carrier resource on which the current cell is located.
 20. Theapparatus according to claim 18, wherein the actual access resourcecomprises a first actual access resource and a second actual accessresource, the first actual access resource corresponds to a first randomaccess configuration, and the second actual access resource correspondsto a second random access configuration, and the first random accessconfiguration and the second random access configuration are uplinkrandom access configurations, and each uplink random accessconfiguration comprises preamble sequences for uplink random access. 21.The apparatus according to claim 18, wherein the program instructionsfurther cause the apparatus to: determine an actual sequence of thesynchronization signal; wherein in sending the synchronization signal,the program instructions cause the apparatus to: send thesynchronization signal on the actual access resource by using the actualsequence.
 22. The apparatus according to claim 18, wherein the resourceindication information is carried by a broadcast channel of the currentcell, and wherein in sending resource indication information, theprogram instructions cause the apparatus to: send the resourceindication information on a broadcast channel resource corresponding tothe actual access resource.